Geothermal Energy Research at Los Alamos National Laboratory

Presented October 5, 2011 at the New Mexico Geothermal Working Group Meeting

Kenneth Rehfeldt

Los Alamos National Laboratory

LA-UR-11-11619

Hot Dry Rock Reports

High Temperature Downhole Tool Multipurpose Acoustic Sensor

• We are developing a truly unique and novel sensor design that is based on acoustics and can determine in real-time and in a single sensor package several parameters: temperature, pressure, fluid flow; and fluid properties, such as density, viscosity, fluid composition, etc. The unique design of the sensor allows its operation at very high temperature and pressure.

Downhole Sensor (cont)

15.05 15.06 15.07

Ampl

itude

(arb

. uni

ts)

Frequency (MHz)

100ppb 200ppb 300ppb 400ppb 500ppb 600ppb 700ppb 800ppb 900ppb 1ppm

Swept Frequency Acoustic Interferometry (SFAI)

Provides data on fluid composition, temperature, pressure, viscosity, and fluid flow

(Sponsor: DOE)

Subsurface Imaging

• High-Resolution Passive and Active Geophysical Imaging – Image fracture and fault zones – Assess microseismic source

mechanism – Detect flow and temperature

distribution • Integration of imaging with

reservoir modeling to enhance flow characterization and prediction

• Teamed with LBL, MIT, NETL, Chevron, Ormat

Initial (upper row) and high-resolution (lower row) mappings of microseismic subcluster from the Fenton Hill geothermal reservoir.

(Sponsor: DOE)

Monitoring and Modeling Fluid Flow in a Developing EGS Reservoir

Awibengkok (Salak) Geothermal Field, Indonesia Project Objectives

• Better understand and model fluid injection into a tight reservoir on the edges of a hydrothermal field • Use seismic data to constrain geomechanical/hydrologic/thermal model of reservoir • Model for flow network to predict injection and production response of reservoir • Use model and data analysis to develop improved stimulation methodologies leading to improved production during EGS development • Approach: Combine analysis of seismic, well log, and flow data to develop improved reservoir model

- Develop and test new analysis and modeling approaches

AWI-18 Injection well

Coupled Hydro-Thermal-Mechanical Modeling Two Projects: Salak Field, Indonesia; Brady’s field, Nevada, USA

Large changes in Pressures, temperatures, stresses Many spatial and temporal scales, Highly nonlinear and coupled Combine micro-earthquake data with modeling Fracture permeability related to shear stress

0

0.5

1.0

1.5

2.0

D e p t h ( k m )

012Horizontal Distance (km)

2300

2400

2500

2600

2700

2800

2900

3000

D e

Faulted, Layered Rock 3D Model 30 years-Temperature contours

Smart Geothermal Tracers

Perfluorinated Hydrocarbon

(PFH)

Shell designed to degrade at temp

00.10.20.30.40.50.60.70.80.9

1

1 10 100

Time, hr

C/C

o

Halide

Naph. Sulfonate

10-nm Quantum Dot

1.E-04

1.E-03

1.E-02

1.E-01

1.E+00

10 100Time, hr

C/C

o

Quantum-Dot Nanocrystal Tracer

Temperature-Indicating Tracer

Smart shell degrades at specified temp and releases thermally-stable nonreactive tracer to indicate temp has been reached. PFH’s have extremely low detection limits

Shell can be designed to be reactive or nonreactive to interrogate surface area

Example of Fracture Surface Area Interrogation in a Single-Well Tracer Test

Simulated breakthrough curves of a halide, a naphthalene sulfonate, and a quantum dot tracer with non-reactive shell in a single-well tracer test (first two are commonly used tracers). Inset shows log normalized concentrations in the tails. The differences between the curves will increase for greater fracture surface area and decrease for less surface area. Note that the quantum dot tracer significantly increases the range of diagnostic responses for interrogating fracture surface area

(Sponsor: DOE)

(teamed with University of Utah)

(teamed with PNNL and BNL Alta Rock, Chevron, U of U)

Pueblo of Jemez – Innovative Exploration Techniques

• Assist the Pueblo to expand resource – Geology (structurally

complex) – Geophysics (seismic,

electrical MT) – Well testing and formation

characterization (tracers, VSP) Indian Springs geothermal well and Jemez students, Earth Day 2009

(Sponsor: DOE)

(teamed with Pueblo of Jemez, New Mexico Bureau of Geology and Mineral Resources, University of Utah, Montana State University)

New Projects – Just Announced Imaging Fault Zones Using Elastic Wave Reverse-Time Migration Imaging

Geothermal Drilling Using Encapsulated Chemical Energy Sources

Capsule Hopper Eductor

Stand Pipe

Mud Pump

Bottom hole drilling assembly

GOALS: - 3 to 6 times improvement in drilling rate in hard, deep rock (granite or basalt). - Reduce number of trips needed to replace worn bottom-hole drilling assemblies. - A factor of three reduction in drilling costs through hard deep rock

Apply high power (> 100 hp) to hole bottom working face through the use of directly applied chemical energy. Proposed chemical energy sources are not exotic nor expensive and are well characterized. Uses typical rotary drilling rig and pipe string configurations.