Internship Report

Internship Report

Dehydration Plant Processing Diagram

1= CONTACTING TOWER 2=LEAN TEG/ GAS HEAT EXCHANGER 3= 3a, 3b & 3c => PUMPS 4=FLASH TANK 5= 5a & 5b => PARTICULATE FILTER 6 = CARBON FILTER 7= LEAN/ RICH TEG HEAT EXCHANGER 8 = SURGE TANK 9 = REBOILER 10 = EXHAUST STAKE 11 = DISTILLED COLUMN

Rich Try Ethylene Glycol

Lean Try Ethylene Glycol

Dehydrated Gas

Fuel Gas

Internship Report

Internship Report

the site to heat the gas due to the reason when pressure is abruptly reduced in result the temperature is decreased widely. In order to avoid the production of hydrates and to protect the pipeline from the corrosion the methanol injectors and corrosion inhibitor injectors are used respectively. Further More Deep Well Production includes:

Pressure Control Valve Flow Control Valves Pressure Safety Valve Methanol Injector Corrosion Inhibitor Injector Line Heater Air Instrument Package

Pressure Control Valve:

Pressure control valve is basically controls the pressure flowing through pipeline, it consists of controller, regulators, Diaphragm head, high pressure regulator and low pressure regulator. It controls the pressure from 3000 psi to 730-750. It is pneumatically controlled and it is supplied at the 120 psi. The pressure of 120 psi is reduced up to 25 psi by high pressure regulator and then low pressure regulator reduces it up to 3 psi. In fact the controller is basically set up to the pressure of 730 psi when it sense the more pressure been supplied than the set pressure it actuates the diaphragm to reduce the area to decrease the pressure or when higher pressure is sensed it actuates the diaphragm to increase the flowing area hence the pressure is increased in the downstream.

Flow Control Valve:

Flow control valve is installed at the site to control the flow of gas through pipe. It is basically executed by control room connected through SCADA (Supervisory Control and Data Acquisition) the operator according to the need of the customer can increase or decrease the flow of gas of all the deep wells.

Pressure Safety Valve:

The pressure safety valve is provided at the deep well site to provide protection from over-pressure of gas in pipe lines. The valve "lets off gas" when safe pressures are

Internship Report

exceeded, then closes again when pressure drops to a preset level.

TIT & PIT:

TIT Stands for Temperature indicator transmitter and PIT stands for Pressure Indicator Transmitter used to indicate the temperature and pressure readings at the site respectively and as well as transmits these readings to control rooms connected through SCADA.

Methanol Injectors:

The methanol injector as the name implies it injects the methanol right after the gas has been supplied from the well head in order to prevent the formation of hydration. It consists of methanol tank, PD pump actuated by instrument air package.

Corrosion Inhibitor Injector:

Corrosion inhibitor injector is used to inject the anti-corrosion chemical into the pipeline in order to avoid the corrosion within the pipeline. It works on the same mechanism as that of the methanol injector and also actuated by instrument air package.

Line Heaters:

Line heater are provided in order to prevent the freezing as the pressure is abruptly reduced from 3000 psi to 730 psi in the result the sometimes temperature is decreased to freezing point.

Instrument Air Package:

At deep wells there are some valves and injectors that require some pressurized source to run their mechanism. As the site is devoid of any compressor to run those instruments like valves and injectors the instrument air package is the one which supplies them the required pressure. As we know that there is the pressure of 730 psi in the pipeline so the air instrument package intakes pressure of flowing gas from pipe line and

Internship Report

Internship Report

At MGCL low pressure well sites the compressors used are the Single Cylinder, Double Acting and Positive Displacement Compressors powered by Single Cylinder, Two Stroke Engine their specification is as follows

Manufacturer: AJAX Engine power Output: 280 HP POWER CYLNDER BORE = 15” POWER CYLINDER STROKE = 16” Compressor Cylinder Bore = 6” Compressor Cylinder Stroke = 11”

Major Components of Compressor are as under:

Reciprocating Engine Mixing Manifold Crankshaft Flywheel Compressor Cylinder Puppet Valves VVP: Variable Valve Pocket Heat Exchanger/Radiator Engine Starter Reservoir / Surge Tank

Working principle of Compressor:

As earlier stated the compressor is powered by 280 HP engine, basically the engine takes the air fuel charge intake through mixing manifold and sucked in at the suction stroke and compress the charge when piston moves towards the cylinder head, at the end of the compression stroke the spark plug ignites the charge and thus the combustion is produced that drives the piston back producing power to rotate the crankshaft.

The flywheel and the compressor pistons’ connecting Rods are also connected to the same crankshaft thus the compressor piston also starts reciprocating. Flywheel is used to store the energy when the power is generated and then release it while required. When the compressor piston reciprocates back and forth by means of crankshaft it sucks the gas from one side and compresses it on the other side and vice versa due to its double acting operation.

Internship Report

Internship Report

BHP & T is operation carried out to determine the bottom hole pressure and temperature. This leads us to estimate the future well production and pressure dropped in a year.

Instruments and Equipments used in BHP & T survey includes:

BOP:

Blow out Preventer is a large valve at the top of the well to control the influx of the information fluids. It is used to avoid the pressure leakage out of well head and it is specifically used in BHP & T survey

Lubricator: it provides housing for the memory gauge during running in hole and pulling out of hole.

Stuffing Box: it prevents leakage of gas from lubricator.

Choke: it controls the production rate by restricting the area available for flow.

Slick Line: it is a thin non electric cable used for selective placement and retrieval of well bore hardware such as plugs, gauges and valves located in the well.

SAS: it is used to record the well head pressure during bottom hole temperature and pressure survey.

Down hole Memory Gauge: it is a device with pressure and temperature sensors to record the down hole pressure and temperature

Operation Procedure BHP & T Survey:

The slick line unit should be placed approximately 100 feet from well head.

Pass slick line through fishing neck and make a special knot on which socket can rotate freely

Program down hole memory gauge prior to commencement of survey

Jack in safety shutdown valve to avoid its operation during the job

Internship Report