3 kick
TRANSCRIPT
Page 1 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
“Modern Well Design”
Drilling Engineering
GEOSCIENCES AND PETROLEUM
ENGINEERING DEPARTMENT
06/December/2011 14:00 – 16:00 &
07 Dec (10:00 – 12:00)
Page 2 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
GEOSCIENCES AND PETROLEUM
ENGINEERING DEPARTMENT
MODERN WELL DESIGN
(06, 07 Dec “10:00 – 12:00”)
ADVANCED CASING DESIGN
(07 Dec “14:00 – 16:00”, 08 Dec “10:00 – 11:00”)
ADVANCED DRILLSTRING DESIGN
(08 Dec “14:00 – 16:00”, 09 Dec “10:00 – 11:30”)
Seminar Room 6, Undercroft, UTP
Page 3 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
Objective
At the end of this course, the attendants should be able to answerthe following questions?
What does the profession of Drilling Engineering mean?How can a well design be initiated?What offset well information to be collected?What is kick tolerance, how is it calculated?How can a kick be identified?What is an AFE, how can it be calculated?What is a bit record, how can the bit cost comparisons bemade?Cementing, operations sequences?What are the practical information in a drilling process?Drillstring design, is it difficult?
It is assumed that the attendants are familiar with subjects which may have beenstudied prior to this course as given below:
Introduction to Petroleum & Natural Gas EngineeringBasic Engineering courses
Page 4 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
Outline
Drilling EngineeringWell DesignRig RequirementsDrilling PlanningOffset WellsKick ToleranceKick IdentificationAFEBit Record/CostCementingPractical InformationDrillString DesignConclusionBackUp Slides
Page 5 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
The goals of the drilling engineerinclude:
providing accurate costestimates,designing well programs thatsatisfy well objectives,reducing cost through theselection of high-efficiencyequipment, systems, andpractices,ensuring safety through therecommendation of soundpractices and through contingencyplanning.
Drilling Engineering
Page 6 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
Responsibilities of a DRILLING ENGINEER
The drilling engineer plays a number of roles in the well planning process.During initial evaluation of a prospect, he or she conducts preliminarystudies and estimates well costs. Once well AFEs are approved, thedrilling engineer:
becomes the designer, coordinator, and monitor of the overall wellprogram.
The responsibilities of the drilling engineer include:gathering and reviewing available data on previous drilling activity inthe proposed areas of operation,preparing initial cost estimates,preparing specific well-cost estimates for Authorization for Expenditurepackages,conducting an initial planning meeting with others involved in specificwell projects to establish objectives for the well,estimating expected formation pressures and fracture gradients,anticipating and addressing the most likely drilling problems,selecting casing sizes and setting depths,providing the data necessary for submitting an application for a drillingpermit,
Drilling Engineering (Cont’d)
Page 7 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
resolving directional drilling requirements,developing the drilling mud program,designing casing strings,preparing a hydraulics program,recommending bottomhole assemblies and bits,preparing cementing recommendations,preparing step-by-step procedures for drilling operations,preparing rig specifications prior to rig bid requests to assist in rigselection,identifying necessary mud-processing and solids-controlequipment,preparing drilling-cost and drilling-time curves to plot predictedperformance,coordinating the well-planning activities of geoscience, purchasing,operations, environmental and regulatory and other engineeringgroups to ensure that all aspects of well program development willmeet schedule commitments.
Drilling Engineering (Cont’d)
Page 8 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
Well Design - Objectives
Proper planning is key to optimizingoperations and minimizingexpenditures.The drilling person’s job is to developoil and gas reserves at minimumcost.
Oil companies are in the businessto make money,If the organization do not makemoney, it cannot stay in business.
The first step in formulating anydrilling plan is to gatherinformation for drilling the well.The selection of casing settingdepths is critical for casing offtroublesome formations, containingpressure, or protecting fresh waterformations.
Page 9 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
Rig RequirementsThe drilling is achieved by means ofhaving properly selected the followingmain items of the rig components:
Power Generation System,Hoisting System,Fluid Circulation System,Rotary System,Well Control System,Drilling data acquisition andmonitoring system.
Other considerations for RigSelection:
Safety Records,Rig mobility and ease ofhandling,Contractor Dependability.Contractual rates (footage, day,turnkey),Condition of all rig equipment.
Page 10 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
Drilling Planning
The drilling engineer is the well architect and planningcoordinator for the drilling project, he/she is in charge of:
Collecting and revising available data for all offset wells,Designing all of the drilling programs (drilling fluid, bit,hydraulics, casing/cementing/ directional drilling, tubulars,BHA and well control aspects),Preparing the AFE (Authorization for Expenditures),Foreseeing the drilling problems, preparing contingencies,Selecting drilling rig and specifications,Preparing drilling cost vs time curves,Preparing and organizing the tenders related to rig andservices,Preparing and organizing the purchasing of the long-leaditems,Making sure that the environmental, regulatory and otherengineering group objectives are met, and the wellprogrammes are executed economically, safely and onschedule.
Page 11 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
Offset Wells’ InformationBest information source for effective Well Planning is collecting informationfrom the offset well data.The following information is of paramount importance:
Daily Drilling Reports,Hydraulics Reports,Tubular Reports,Mud Reports,BHA (Bottom Hole Assembly),Directional Surveys,Drilling Bit Records,Electric Wireline Loggings,Casing and Cementing Reports,Geological Information,Reservoir Characteristics,Logistics,Weather conditions,Service Company recommendations,Government Regulations,Problems Encountered,Success and Failed Reports of the attempted solutions for the problemsoccurred.
Page 12 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
MJ-2
GroundHammar
Upper Fars - Dibdiba
Lower Fars
Ghar
Damman
Um Er-Radhuma
AalijiShiranish
Hartha
Sa'di
Tanuma
Khasib
Mishrif
Rumalia
Ahmadi
Mauddud
Nahr Umr
Shuaiba
Zubair
Ratawi
Yamama
TD
42" CP
30" CSG
20" CSG
13 3/8" CSG
9 5/8" CSG
7" Liner
ML (Minor) Start
ML (Minor) End
ML
ML Severe (Gas Kick)
Water Ingression
MJ-3
GroundHammar
Upper Fars - Dibdiba
Lower Fars
Ghar
Damman
Um Er-Radhuma
Shiranish
Hartha
Sa'di
Tanuma
KhasibMishrif
Ahmadi
Mauddud
Nahr Umr
Shuaiba
Zubair
Ratawi
Yamama
SulaiyTD
30" CSG
20" CSG
13 3/8" CSG
9 5/8" CSG 7" Liner
4 1/2" Liner
Partial ML
Partial ML
Partial ML
Stuck Pipe
Collapse (9 5/8in CSG)
Well Deviated
MJ-4
GroundHammarUpper Fars - Dibdiba
Lower Fars
Ghar
Damman
Um Er-Radhuma
Aaliji
Shiranish
Hartha
Sa'di
Tanuma
Khasib
Mishrif
RumaliaAhmadi
Mauddud
Nahr Umr
Shuaiba
Zubair
Ratawi
Yamama
TD
30" CSG
20" CSG
13 3/8" CSG
9 5/8" CSG
7" Liner
MJ-5
GroundHammarUpper Fars - Dibdiba
Lower Fars
Ghar
Damman
Um Er-Radhuma
Aaliji
Shiranish
Hartha
Sa'di
Tanuma
Khasib
Mishrif
RumaliaAhmadiTD
20" CSG
13 3/8" CSG
9 5/8" CSG
7" Liner
ML
Water Ingression
MJ-6
GroundHammarUpper Fars - Dibdiba
Lower Fars
Ghar
Damman
Um Er-RadhumaAaliji
Shiranish
Hartha
Sa'di
TanumaKhasib
Mishrif
RumaliaAhmadi
TD
20" CSG
13 3/8" CSG
9 5/8" CSG
7" CSG
ML (Total)
ML
Deviation Start
Deviation End
MJ-7
GroundHammarUpper Fars - Dibdiba
Lower Fars
Ghar
Damman
Um Er-Radhuma
Aaliji
Shiranish
Hartha
Sa'di
TanumaKhasib
Mishrif
RumaliaAhmadiTD
30" CSG
20" CSG
13 3/8" CSG
9 5/8" CSG
ML
ML (Total)
Overpull (50 tons)
Gas Cut Mud
Caving (Start)
Caving (End)
MJ-8
GroundHammarUpper Fars - Dibdiba
Lower Fars
Ghar
Damman
Um Er-Radhuma
Aaliji
Shiranish
Hartha
Sa'di
TanumaKhasib
Mishrif
RumaliaAhmadi
Mauddud
Nahr Umr
Shuaiba
Zubair
Ratawi
Yamama
Sulaiy
TD
42" CP
30" CSG
20" CSG
13 3/8" CSG
9 5/8" CSG
7" Liner
ML
ML (Stopped)
Fishing
Fishing
Fishing
MJ-9
GroundHammarUpper Fars - Dibdiba
Lower Fars
Ghar
Damman
Um Er-Radhuma
Aaliji
Shiranish
Hartha
Sa'di
TanumaKhasib
Mishrif
RumaliaAhmadi
Mauddud
Nahr Umr
Shuaiba
Zubair
Ratawi
Yamama
SulaiyTD
30" CSG
20" CSG
13 3/8" CSG
9 5/8" CSG
7" Liner
ML (Start)
ML (End)
ML (Start)
ML (End)
ML (Start)
ML (End)
Stuck Pipe
ML in Cementing
-15
485
985
1485
1985
2485
2985
3485
3985
4485
Dep
th, m
TVD
ss
Collecting Offset Wells’ Information
RT, 0 m
30 in. CP @ 100 m
18 5/8 in. CSG @ 1338 m
16 in. CSG @ 2490 m
7 in. Liner @ 5750 m
Overb
urd
en
Gra
die
nt
Po
re G
rad
ien
t
U.Fars-Dibdiba (sst,sh,ms), 30 m
L.Fars (lst,sh,ms,eva), 909 m
Ghar (sd,lst), 1234 m
Damman (lst), 1338 m
Um Er-Radhuma (lst), 1572 m
Aaliji (lst), 1880 m
Shiranish (lst,sh,ms), 1991 m
Hartha (lst), 2144 m
Sa'di (lst), 2276 mTanuma (lst), 2384 m
Khasib (lst), 2431 m
Mishrif (sh,ms,lst), 2490 m
Ahmadi (sh,ms,lst), 2744 m
TOC 250 m
TOC 1188 m
TOC 5165 m
Rumalia (lst), 2712 m
Mauddud (lst), 2901 m
Nahr Umr (sst), 3079 m
Shuaiba (lst), 3266 m
Zubair (sst), 3417 m
Ratawi (sst,sh,ms), 3705 m
Yamama (lst), 3782 m
Sulaiy (lst), 4144 m
Gotnia (lst,sh,ms, salt), 4425 m
Najmah (lst), 4759 m
24 1/2 in. CSG @ 400 m
MJ-2 DST-1
MJ-2 DST-17
MJ-2 DST-22
MJ-9 RFT
MJ-11 Actual Mud Den
MJ-19 Actual Mud Den
MJ-3 Actual Mud Den
MJ-9 Actual Mud Den
MJ-15 Actual Mud Den
MJ-17 Actual Mud Den
Sargelu (lst,sh,ms), 5169 m
Alan (lst,eva), 5233 m
Mus/Adaiyah (lst,salt,eva), 5315 m
Butma (lst,sh), 5502 m
R-N-172_RFT (Najmah_RFT_PP-Gradient)
R-N-172_LOT
Mishrif
Yamama
Gotnia
Najmah
20" CSG_R-N-172
13 3/8" CSG
9 5/8" CSG
7" Liner
Hartha
Cmt (LC) Top
Cmt (LC) Btm
TOC 2340 m
TOC 4609 m
13 3/8 in. CSG @ 3783 m
9 5/8 in. CSG @ 5315 m
Kuwait-Frac
11 3/4 in. Liner @ 4759 m
TOC 3633 m
0
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2750
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5250
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5750
0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 3.0 3.1 3.2 3.3 3.4
Dep
th, m
TV
DR
T
Pressure Gradient [kgf/cm2 / 10 m]
NEWFIELD-TRIASSIC_WELL PPFG Graph (All depths are referenced to RT= 0 m).
Page 13 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
Prior to designing casing strings,the engineer must study pressurerequirements and prepare a mud-density schedule.
A plot of fracture gradient versusdepth should be prepared, althoughin some instances knowledge of thefracture gradients at the casingdepths under study is sufficient.
Leakoff data on new wells isparticularly valuable.
Hole problems must be thoroughlyidentified and the need to designfor acid gases or other corrosionproblems evaluated.
Prior Design
Page 14 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
Kick Tolerance
Kick Tolerance is the maximum allowable influx volume, for aknown or assumed SIDPP, which will not cause the formation tofracture when either the influx is at the bottom of the annulus orwhen it is circulated and expanded to the casing shoe by aconstant bottom-hole pressure method.
Maximum tolerable length (H) of gas influx in the annulus at anyposition between bottom hole and the casing:
Where:Hmax = height of gas bubble at casing shoe, ftMW = maximum mud weight for next hole section, ppgTD = next hole total depth, ftCSD = casing setting depth, ftFG = fracture gradient at the casing shoe, ppgPf = formation pore pressure at next TD, psiG = gradient of gas, 0.1 psi/ft
Page 15 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
Current well design guidelines prescribe a limit of 100 barrelsminimum kick tolerance for the design of a casing programme.The limit of 100 barrels has been used successfully since itsintroduction in 1986.Recent developments in drilling, such as slim and downsized welldesigns have prompted a reappraisal of the minimum design kicktolerance.These drilling developments have coincided with other analysistechniques that can provide improved kick detection capabilityand through simulation, a better understanding of the behaviourof kicks in the wellbore.For this reason International Oil Companies require their planningpersonnel calculate the Kick Tolerances for all surface andintermediate casing for all well for the defined minimum volumes.For example the minimum kick tolerance for a 12 ¼” hole is 100bbl where as for a 8 ½” hole is 50 bbl. For holes smaller than 8½” the Kick Tolerance is 25 bbl.
Kick Tolerance (Cont’d)
Page 16 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
Ref: Practical Well Drilling & Planning Manual
Page 437
in
Pipe OD 5
MAASP Hydrostatic Pressure of the gas
750 psi 54 psi
Formation Pressure Hydrostatic Pressure of Half of the height of the gas
5280 psi 27 psi
Pressure at the top of the gas bubble Annular Capacity
3750 psi 0.121491 bbl/ft
13 3/8" CSG Shoe Depth OH Length Influx Volume
ft 5000 FRAC GRAD 0.75 psi/ft 3000 ft 65.60496 bbl
Pressure in the OH section Pressure in the Centre of the gas Bubble
GAS GRAD 0.1 psi/ft 1530 psi 3777 psi
Mud Grad x OH Length Calculate the volume of this gas at the next casing point
1800 Pressure in the centre of the gas bubble at the CSG Shoe
Gas Influx Length 5253 psi
Hole Size in 12 1/4 540 ft Using Boyle's Law P1V1/P2V2 find the kick Tolerance
Kick Tolerance
47.17 bbl
TD ft 8000 MUD GRAD 0.6 psi/ft
PORE GRADIENT0.66 psi/ft
KICK TOLERANCE
Kick Tolerance (Cont’d)
Page 17 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
Kick Tolerance (Cont’d)
Page 18 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
Kick Tolerance (Cont’d)
Page 19 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
KICK_TOLERANCE__CSG_SEAT_by_Depth_COUNTRY_NEWFIELD
0
500
1000
1500
2000
2500
3000
3500
4000
4500
0.00 20.00 40.00 60.00 80.00 100.00 120.00 140.00 160.00
Dep
th, m
TV
D R
T
Kick Tolerance, m3
Kick Tolerance Graph
Kick Tolerance, m3 Company Min Kick Tolerance, m3
0
500
1000
1500
2000
2500
3000
3500
4000
4500
0.00 20.00 40.00 60.00 80.00 100.00
Dep
th, m
TV
D R
T
Max Allowable Surf Pres (Choke Margin), kgf/cm2
Max Allowable Surf Pres (Choke Margin)
Max Allowable Surf Pres (Choke Margin), kgf/cm2 Company Min MAASP, kgf/cm2
0
500
1000
1500
2000
2500
3000
3500
4000
4500
0 20 40 60 80 100 120 140
Dep
th, m
TV
D R
T
Differential Pressure, kgf/cm2
Differential Pressure
Differential Pressure, kgf/cm2
Kick Tolerance (Cont’d)
Page 20 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
Kick Tolerance - ExampleCalculate the kick tolerance for the following well information:
9 5/8" Casing = 14500 ftNext TD = 17000 ft
FG at 9 5/8" Casing Shoe = 16 ppgMaximum mud weight for the next hole = 14.5 ppg
Maximum formation pressure at next hole = 14 ppgGas Gradient= 0.1 psi/ft
Next hole diameter = 8 1/2 inWorkstring in the hole (from surface to TD) = 5 in
Solution:
Hmax= 2405 ft
Volume at shoe = H x Capacity between hole/drillpipe
Capacity= 0.045900525 bbl/ft
V1= 110.4 bbl, volume of bubble at the shoe
Using Boyle's Law P1V1=P2V2
V2= 107.6 bbl, volume of the bubble at the TD
Page 21 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
The Volume for any tubular is calculated by means of the followingformula:
Where VFluid = Volume of the fluid, bblL = Length, ft
Kick Tolerance – Example (Cont’d)
The Volume for any annular is calculated by means of the followingformula:
Page 22 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
Kick Identification
Gradient, psi/ft Gradient, sg Gradient, ppg Influx Type
0.05 - 0.2 0.115 - 0.461 0.96 - 3.85 Gas
0.2 - 0.4 0.461 - 0.923 3.85 - 7.70Probable combination of gas, oil, and/or salt water
0.4 - 0.5 0.923 - 1.153 7.70 - 9.63 Probable oil or salt water
In case of a kick occurrence the type of the influx that enters thewellbore is required to be determined.The influx gradient can be evaluated using the given ranges.
A gas kick causes higher annular pressures than a liquid kick.A gas kick has lower density than a liquid kick.A gas kick must be allowed to expand as it is pumped to surface.The objective for the well control is to always having a constantbottom hole pressure. This is only possible through having highersurface annular pressure that can be maintained through theadjustable choke.
Page 23 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
Kick Identification (Cont’d)
Equation for the determination of the density of kick:
Where,ρkick = Kick density, ppgρmud = Mud density, ppgPCasing = Casing pressure, psiPDP = Drill pipe pressure, psiLk = Length of the kick fluid, ft
Page 24 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
Kick Identification - ExampleA well is being drilled vertically with the following information when itbegan to flow. Following the pit gain the pump(s) are stopped, and theBOPs are closed.
TD = 12000 ftMW = 10 lbm/gal
Flow Rate = 9 bbl/minMud gain = 25 bbl
Time period during the gain = 5 min
SIDPP = 600 psiICP = 800 psi
Annular Capacity of casing = 12.9 ft/bbl
Length of DCs = 815 ft
Annular Capacity (DC) = 28.6 ft/bbl
a) Compute the density of the kick?b) Assume that the kick fluids are mixed withthe mud pumped while the was flowing. Re-calculate the density of the kick?
Page 25 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
Kick Identification – Example (Cont’d)
SOLUTION:a) Total Capacity opposite the DCs is required to be calculated.
VDC = 31.5bbl lessMud gain = 20 bbl
If it is assumed that the kick fluids entered as a slug, then the volume of kickfluid is less than the total annular capacity opposite the drill collars.
Length of the kick fluid is calculated multiplying the mud gain with thecapacity across the DCs.
Lk=572ft
ρkick = 2.9ppg
A kick density less than about 4 ppg should indicate that the kick fluid ispredominantly gas, and a kick density greater than about 8 ppg shouldindicate that the fluid is predominantly liquid.
Page 26 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
Kick Identification – Example (Cont’d)b)
If it is assumed that the kick fluids are mixed with mud pumped while the wellwas flowing.
Vkick mixed =45.5 bbl Vmud pump =25.5 bbl
The length of mixed zone is Lkick =1081 ft
Using the given kick density equation: ρkick = 6.04 ppg
The given density implies that the kick fluid is predominantly liquid.Since the column of the mixed zone is only 1081 ft long and under highpressure, the mean density can be related to the kick fluid density using theequation for mixtures.
ρkick = 1.5 ppg
Even though the effect of mud pump is considered the predominant kickdensity indicated that it is a gas.
Page 27 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
AFE
Page 28 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
AFE (Cont’d)
Page 29 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
AFE (Cont’d)
The cost estimate sheets are usually prepared in three sections:The left column shows a code and a description for each line,The middle set of columns are used to enter time or depth-dependent rates,The right set of columns either multiplies time or depth-related costs by the relevant figure.
Page 30 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
OFFSHORE PETROLEUM CORPORATION DRILLING & COMPLETION
WELL KAYA-2 DEPTH: MODU NAME:
SELECT DATE 22 May 2006 243 5.00 m RT TURN
REP.NO 80 Spud Date: 31/January/2006
ESTIMATED INTANGIBLE EXPENSES DATE PREVIOUS TOTAL
ACCOUNT DESCRIPTION 22 May 2006 21 May 2006
401 MOB / DEMOB RIG COST 0 0 0
402 RIG POSITIONING 0 0 0
403 DAILY RIG COSTS 72,008 78,573 5,097,348
404 FUEL / LUBE / POWER / WATER 2,543 2,680 324,896
405 BITS & MILLS 0 0 69,070
406 DAMAGE, STORM OR OPERATIONAL DELAY 0 0 574,600
407 DRILLING MUD / CHEMICALS / RELATED SERVICES 0 0 154,243
408 CONTRACT LABOUR 10,600 10,600 196,255
409 OPEN HOLE LOGGING / LWD 1,000 1,000 437,420
410 CASED HOLE LOGGING / WEIRELINE 0 0 224,560
411 DOWNHOLE COMPLETION SERVICES 0 0 203,363
412 MUD LOGGING UNIT 1,800 1,800 192,900
413 FORMATION EVALUATION 0 0 88,163
414 FISHING TOOLS / SERVICES / PIPE RECOVERY 0 0 0
415 CEMENTING JOB 0 0 42,480
416 CEMENT & PUMPING SERVICES 0 0 136,618
417 SUPPLY VESSEL 7,500 7,500 585,000
418 PERSONNEL TRANSPORT BOAT 417 417 42,900
419 DOCK, STORAGE, CRANE SERVICES 1,422 1,422 110,916
420 SHIPPING AGENT 461 461 35,958
421 EQUIPMENT RENTAL 1,000 1,000 91,940
422 CASING TUBING RUNNING TOOLS 0 200 36,890
423 HAMMER EQUIPMENT RENTALS & PERSONNEL 0 0 0
424 DIRECTIONAL DRILLING SERVICES 0 0 504,672
SUB-TOTAL INTANGIBLE 98,751 105,653 9,150,191
TANGIBLES
300 CONDUCTOR 0 0 190,190
301 CASING 0 0 528,052
302 TUBULARS 0 0 52,538
304 CHRISTMAS TREE 0 0 0
303 WELL HEAD EQUIPMENT 0 0 80,940
305 DOWN HOLE EQUIPMENT 0 0 59,452
SUB-TOTAL TANGIBLES 0 0 911,172
ADMINISTRATIVE EXPENCES
441 WELL PLANNING 984 984 76,752
442 OPERATIONS & DRILLING MANAGERS 3,497 3,497 272,766
443 PROJECT MANAGEMENT 1,628 1,628 126,984
444 SHORE BASE STAFF 695 695 54,210
445 ACCOUNTING TEAM 58 58 4,524
446 ENVIRONMENTAL PROTECTION 410 410 31,980
447 TRAVEL AND ACCOMODATIONS 1,732 1,732 135,096
448 SHORE BASE OFFICES AND RENTAL 723 723 56,394
449 COMMUNICATIONS 536 536 41,808
450 TAXES & ASSOCIATED COST 4,395 4,395 342,810
451 CUSTOM AGENT FEES 200 200 15,600
452 CUSTOM CLEARANCE & TRANSPORTATION 669 669 52,182
453 BANK CHARGES 184 184 14,352
454 RIG CREW ADMINISTRATIVE 508 508 39,624
455 INSURANCE 1,000 1,000 78,000
456 TRANSLATION AND OTHER EXPENCES 180 180 13,860
SUB-TOTAL ADMINISTRATIVE 17,399 17,399 1,356,942
TOTAL DAILY COST, USD 116,150 123,052 11,418,305
NOTE
AFE preparation requires athorough geological andgeophysical report, a costestimate for drilling andcompleting the well, and aneconomic analysis of theproposal.Preparation of well-costestimates requires research ofoffset well performance toreview the problemsencountered, the materialsused, and the effectiveness ofthe well programs (mud,cementing, casing, etc.)attempted.
AFE (Cont’d)
Page 31 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
Bit Record
Bit records contain a wealth ofinformation essential to theDrilling Engineer.Bit records could give usefulinformation whether the bitrun was economical or not.The heading of the bit recordprovides information such asoperator, contractor, rignumber, well location,drillstring characteristics, andpump data.In addition the bit headingprovides dates for spudding,drilling our from under thesurface casing, intermediatecasing depth and reaching thehole bottom.
Page 32 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
Bit Record (Cont’d)
Page 33 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
Bit Run Cost Equation
whereCd = Drilling cost for bit run, USD/ftCb= Cost of bit run in hole, USDCr = Rig cost, USD/dTd = Drilling time, hTt = Trip time, hTc = Connection time, hDf = Formation interval drilled, ft
The cost of constructing a well is composed of a variety ofexpenses mainly rental costs, material and services.
Page 34 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
Bit Run Cost Equation - Example
The lowest drilling cost is 56.3 $/ft.
Bit drilled the mostinterval is 605 ft (BIT D).The lowest drilling cost is56.3 $/ft (BIT B).The bit interval cost areranging in between13,550 – 37,150 $.The chart showing thedrilling cost comparisonfor all bits are as givenbeside.
BitBit Cost,
USDRotating Time, h
Connection Time, h
ROP, ft/hBit Run
Cost, $/ftInterval
Drilled, ftInterval Cost, $
A 1000 15 0.1 14 64.5 210 13,550
B 3000 35 0.2 13 56.3 455 25,600
C 4000 45 0.3 10 70.3 450 31,650
D 4500 55 0.3 11 61.4 605 37,150
Page 35 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
Cementing – Single Stage
Page 36 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
SINGLE STAGE CEMENTING
Prior to the cementing operation make sure the internal diameters of the cementing
head and outer diamaters of the plugs are measured, so that all of the plugs to be
used will be easily passing through the cementing head.
Explanation
1 Test the Cement lines up to 2000 psi.The test pressure magnitude should be up to the expected
highest pumping pressure.
2 Pump 50 bbl Spacer.
The purpose of the spacer is to condition the hole in order
fot the cement to make a good bonding. The spacer is
desired to flow in a turbulent flow state, and remain across
the open hole for a certain amount of time.
3 Drop BOTTOM PLUG; and place the top plug into the CEMENTING HEAD.It is important that during droppig the plugs the cementing
head's cap will not be opened.
4 Pump LEAD SLURRY: 101.5 bbl. Pump TAIL SLURRY: 35.3 bbl.Make sure the correct volumes are pumped. Measure
previously prepared "water volumes".
5 Drop TOP PLUG. Observe the flag for the indication to confirm the plug drop.
6 Pump 2 bbl of water in order to flush the cementing lines from cement.
Make sure enough amount of water is going to be pumped
and the cementing lines will be cleaned for future use, clear
of any cement.
7Displace cement with 290.5 bbl of drilling mud using mud pumps. The total number of
strokes are 3825. The pump output considered is: 3.19 gal/stroke.
Calculate the pump output before the cementing operation,
and make sure measure the pump volumetric efficiency is
considered in the calculations.
8
Set the plug and observe the well for a back pressure and leak. Expected plug set
pressure should be approximately: 445 psi [Excluding Frictional Pressure Losses]. Test
the plug to 945 psi for 15 MINUTES.
When getting closer to set the plug, make sure the pump
rate is reduced to minimum.
9 Wait for Cement to harden.Wait for cement based on the recommendation of the
cementing contractor. Observe the surface samples.
SEQUENCE of OPERATIONS
Cementing – Single Stage – Cont’d
Page 37 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
Cementing – Two Stage
Page 38 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
Cementing – Two Stage – Cont’d
Page 39 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
Practical InformationImportant and useful practical information for the Rig Site Drilling Engineers:
Always keep it as simple as possible.Data acquisition during the course of an drilling operation is vital.The deeper the formations get, the more the abnormal pressures may increase, acasing must be set before reaching a high pressure formation.Do not believe everything you hear at the rig site, investigate and makenecessary calculations to comprehend the happening.A short trip is not a necessity every day, you do not have to do this if the hole isclean.Spend ample amount of time at the rig site to become familiar with operations.Write a procedure if you have seen it done. Report success and failures alike. Donot place blames, find solutions.Involve field personnel as part of the planning implementation operations.Bit weight will certainly effect the Penetration Rate as much as Bit Rotation will, ifhydraulics are adequate apply 5-6 klbf/in bit diameter as a general rule of thumb.For insert bits apply 2.5-3 tons/in of bit size.Softer Formations require more hydraulics than harder formations:
Apply 4-5 HHP/in2 for SOFT Formations,Apply 2-3 HHP/in2 for HARD Formations,
Insert bits do not like HIGH RPMs.Drilling record in 24 hours is by 3050 m in a 12 ¼” hole diameter drilleddirectionally by Philips Petroleum.In North Sea the formations are usually very soft.Remember Barite is a relatively inactive weighting particle.As the filtration rate decreases the penetration rate decreases as well.A shale formation would never squeeze into a wellbore.
Page 40 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
Important and useful practical information for the Rig Site Drilling Engineers:Bit ballings are of the biggest problems associated with the PDC bits.PDC bits are usually run on performance basis, consider renting PDC bits.Tungsten carbide does not erode!Nozzles larger than 15/32 inch will have no trouble in passing LCM material.In case of getting a stuck pipe immediately PULL or SLACK OFF (Jar) to themaximum permissible magnitudes.Usually assume the following pump efficiency values:
TRIPLEX Pump 95-98% of Efficiency,DUBLEX Pump 85-90% of Efficiency.
There is almost NO frictional annular pressure loss difference up inthe annulusexcept the section of DCs.Hydraulics are not optimized but maximized. Hydraulics can be maximized usingthe HORSE POWER method or the IMPACT FORCE methods.
Hydraulic Horse Power will be maximized when 35% of the total pressurelosses of circulating system are lost at the bit.Impact Force will be maximized when 48% of the total pressure losses ofcirculating system are lost at the bit.
The following tendencies are observed for the PENETARTION RATE performance:Increasing bit weight increases penetration rate,Increasing RPM increases penetration rate,More HHP/in2 increases penetration rate,Increasing MW decreases penetration rate,Increasing solids content decreases penetration rate,Higher viscosity (especially at low shear rates) decreases penetration rate,Decreasing fluid loss decreases penetration rate.
Practical Information (Cont’d)
Page 41 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
Practical Information (Cont’d)Important and useful practical information for the Rig Site Drilling Engineers:
It is a good sign to have the roller cone bits to have worn out by teeth to the half.Remember the diameters, generally:
Casing ≥ 4 ½”Tubing ≤ 4 ½”
8 round and BTC thread connections should be DOPED to have seal.Extremeline is an integral joint, with no coupling.The more the tension in a pipe the less the COLLAPSE occurrence.For a trip margin make sure that the MW is 0.5 ppg greater than the POREPRESSURE.For a safe drilling make sure the ECD is 0.5 ppg less than the FRACTUREPRESSURE.Most frequent failures are seen in tension design of the CASING DESIGNAPPROACH.The following Design Factors are used:
TENSION 1.6 to 2.0COLLAPSE 1.0 to 1.125BURST 1.0 to 1.25Pipe Body 1.5 to 1.8
Maximum Fracture Gradient is 1 psi/ft.0.1 psi/ft is the gas gradient.Casing joints generally have a lower Collapse value then it has a Burst value.Gate valves hold pressure both way.Temperature is important prior to cementing operation.
Page 42 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
Practical Information (Cont’d)Important and useful practical information for the Rig Site Drilling Engineers:
Cement displacement should be at a rate of 200ft/min. The annular velocity isrequired to be maximized.Weight Indicator (MARTIN DECKER) is a relative indicator.When the weather is hot the indicator will weight more.The best surveying method in directional drilling is “Minimum Curvature Method”.The following drilling tendencies will occur with the given bed dippings:
If the bed dip < 45 deg from vertical, the bit will have a tendency to deviateup dip.If the bed dip > 65 deg from vertical, the bit will have a tendency along thebed dip or follow it.If the 45 deg < bed dip from vertical < 65 deg, the bit can do either.
In Saudi Arabia the production is mostly from the Limestone reservoirs, theformation is so strong that it does not deform even when multi-lateral wells aredrilled.In directional holes it is the DLS that causes Torque and Drag.A pendulum or slick assembly up to 1-2 degrees has got to-do the same.A pendulum assembly works at inclinations above 4-5 degrees.You obey the laws Mother Nature makes, or you pay the consequences.
Other PointsThe principal purpose of casing is to ensure the integrity of the well during drilling andproduction.Casing design evolves from completion requirements, as the completion equipmentdictates the size of the production casing or liner.Tubular strengths are selected as the well conditions dictate, and materials areselected to resist corrosion.
Page 43 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
The success of failure of a well, from a drilling point ofviewpoint, is heavily dependent on the quality of wellplanning prior to spud.
The quality of the well planning in turn is heavily dependentof the quality and completeness of the data used inplanning.
The successful drilling engineer is a natural detective,snooping around for every snippet of useful data toanalyze and consequently implement into the well planningand ensure the implementation.
Conclusion
Page 44 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
References
Azar J.J., Samuel G.R., “Drilling Engineering,” PennWell Publishing Company, Tulsa, OK, 2007
Bourgoyne, A., Millheim, K., and, Young, F.S.,: “Applied Drilling Engineering,” SPE Textbook, Societyof Petroleum Engineers, Richardson, TX, 1986
Carden, R.S., Grace, R.D., and, Shursen, J.L.,: “Drilling Practices,” Petroskills-OGCI, Course Notes,Tulsa, OK, 2006
“Well Control for the Rig-Site Drilling Team”, Aberdeen Drilling Schools & Well Control Training Centre,V4 Rev March, Aberdeen 2002
Mitchell R. Ed. “Petroleum Engineering Handbook – Drilling Engineering,”, Volume II The Society ofPetroleum Engineers, Richardson, TX, 2006
Johancsik C.A, Friesen D.B., Dawson R., “Torque and Drag in Directional Wells – Prediction andMeasurement,”, SPE 11380, Journal of Petroleum Technology, pp 987-992, June 1984
Devereux S., “Practical Well Planning and Drilling Manual,” PennWell Publishing Company, Tulsa, OK,1998
Page 45 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
45
THANKS FOR YOUR
TIME
Questions?
Page 46 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
BACK-UP SLIDES
Page 47 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
Seven factors have been identified as the main contributors to theresultant shut in volume once a kick occurs; these are:
The formation permeability and porosity,The rate of penetration or the length of exposed formation,The hole size,The kick intensity,The method used for kick detection,The crew reaction times to alarms and the time taken to performa kick drill,The time taken to close the BOP and/or the choke.
The Factors Controlling Shut In Volumes
Page 48 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
Force, Work, Torque and PowerThe following equations are very important for the engineering calculations:
Massis the quantity of matter in an object and is constant on earth as well as inspace.
Units of mass: kg (kilogram), 1 metric ton, 1 t = 1000 kg
ForceF=m x aForce = mass x accelerationUnit of force: N (Newton), (N = kg.m.s^-2)Practical use: daN, kN, MN
WorkEnergy is force x distance (N.m)Unit of work: J (Joule)Practical use: kJ, MJ
TorqueTorque is the tendency of a force to rotate an object about an axis.Unit: N.m (newton-metre)Practical use: klbf-ft
Poweris the work/unit-timeUnit of power: W (Watt)Practical use: kW, MW
Page 49 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
Hole Cleaning Sketch
Laboratory work has demonstrated that drilling at an inclinationangle greater than approximately 30° from vertical posesproblems in cuttings removal that are not encountered in verticalwells.
Page 50 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
Well Planning/Drilling Engineering
Many commercial software vendors provide a suite ofdrilling-engineering applications that enable:
casing/tubing design,torque/drag, hydraulics,hole cleaning,swab/surge,well control,cementing,drillstring-vibration/directional-performance,wellbore-stability analysis to be performed.
These engineering systems enable well planners to designthe well within concise engineering constraints.These planned models are updated during the drillingprocess to monitor the well and to ensure that designconstraints are not exceeded.
Page 51 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
Well Control (No Expansion)
In a gas reservoir the pressure at the top of the reservoir is higher. As yougo deep the pressure decreases due to mother nature, and rules of physics.However when a tubing string in which gas is flowing considered, thepressure at the top is less as compared to pressure at the bottom.
Page 52 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
ERD Wells
Page 53 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
ERD Wells (Cont’d)
Page 54 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
ERD Wells (Cont’d)
Page 55 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
Balanced Plug Cementing
Page 56 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
Balanced Plug Cementing (Cond’t)
PLUG CEMENT PROCEDURE
1 Conduct safety meeting ahead of pressure test of the lines.
2Fill the lines and pressure test the lines first to 500 psi 5 min, then 2500 psi 10 mins.
3Mix cement volume of 23.03 bbl of cement taking into consideration of the container's dead volume, that could not be sucked, (sample composition to be 44% water, 0.8% D-65, 0.2% Baracor).
4 Pump 20 bbl of fresh water using the cementing unit.
5 Pump 23.03 bbl of PLUG cement.
6 Pump 7.74 bbl of fresh water after the cement.
7 Displace cement with 108.21 bbl of active system mud.
8 Trip the open ended DP string slowly just above the anticipated cement top.
9Reverse circulate and observe the fluid return at the surface, fresh water should be observed.
10 Wait on cement thickening.
11 RIH with open ended tubular and tag top of the cement plug.
Page 57 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
Bit Size, in Casing OD, in Clearance, in
36 30 3.00
26 20 3.00
17 1/2 13 3/8 2.06
12 1/4 9 5/8 1.31
8 1/2 7 0.75
6 4 1/2 0.75
Clearance Between the Bit and the Casing OD
Page 58 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
Conventional Casing Profile
Lean-Profile
Wells drilled with different Profile Technology are concluded in considerably less daysthan conventionally drilled ones.
From an economical point of view, the following observations can be made, related toLean Profile technology:
The additional cost for the use of automatic drilling systems are nearly paid by the cost savingof less material consumed and less cost requirements for waste management.
The drilling time saving of the different Profile Technology application is the most significanteconomical issue.
Casing Profiles
Page 59 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
Differential Sticking
Page 60 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
Differential Sticking – Example
Example:
6.125in hole is being drilled through a100 ft depleted gas sand. The pressure in the wellbore is2000 psi greater than formation pressure of the depleted sand.
The mud cake has a thickness of 0.5 in and a coefficient of friction of0.1.
If the 4.75in collars become differentially stuck over the entire sandinterval, what force would be required to pull the collars free?
Solution:
Effective area of contact A
A = 5645 in^2
Freeing force is calculated,
Fst = 1,128,972 lbf
Page 61 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
Differential Sticking – Cont’d
Given equations indicate that the following factors tend to increasethe sticking force:
1 High wellbore pressure caused by unnecessarily high muddensity,2 Low formation pore pressure in permeable zone (depleted oilor gas sand)3 Thick, permeable formation, which causes greater effectivearea,4 Thick mud cake, which causes a greater effective area,5 Large pipe diameter, which causes a greater effective area6 A mud cake with high coefficient of friction.
Thus,Mud having a low density, a low water loss, and a thin, slick
mud cake are best for preventing differential pressure sticking.
Page 62 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
Cementing
Page 63 of 63GEOSCIENCES AND PETROLEUM ENGINEERING DEPARTMENT, Modern Well Design
Economics of drilling and cementing dictate that thesecasing points be as far apart as formation pressures andhole stability will allow.
Use of small casing severely restricts the opportunities fordeepening the well or using larger pumps.
Use of small casing to save on drilling costs is usually a poorchoice in any area in which high production rates (includingwater floods) are expected.
Cementing (Cont’d)