The primary goal is to show that microholes provide downhole access at significantly lower cost than conventional wells and provide superior acoustic performance when compared with the use of temporarily converted production or injection wells. A secondary goal of the project is to evaluate new prototypes of commercial drilling equipment. The Los Alamos National Laboratory microdrilling rig serves as a platform to evaluate commercial technology that is suitable for microdrilling and completion service.

Program
This project was funded through the Department of Energy's Natural Gas and Oil Technology Partnership Program. The Partnership Program establishes alliances that combine the resources and experience of the nation's petroleum industry with the capabilities of the national laboratories to expedite research, development, and demonstration of advanced technologies for improved natural gas and oil recovery.

Los Alamos National Laboratory (LANL),
Los Alamos, NM

Lawrence Berkeley National Laboratory (LBNL), 
Berkeley, CA

Rocky Mountain Oilfield Testing Center (RMOTC), 
Casper, WY

Providers of geophysical data to the oil and gas industries seek low-cost access to the subsurface for the emplacement of seismic instrumentation for a variety of purposes. LANL's experience with seismic data acquisition in oil fields indicates that low-cost, dedicated microholes for deployment of seismic sensors are needed to enhance acoustic data monitoring of the subsurface. Dedicated data aqusition holes provide reduced natural surface and cultural noise, reduced or eliminated seismic-signal travel paths through highly attenuating surface layers, and a greatly improved signal-to-noise ratio. 

Accordingly, microholes promise a low-cost alternative to conventional wells; they can be placed in the desired location and designed for optimal acquisition of seismic data.

Project Results
Microdrilling to 820 feet in an oil field has been demonstrated successfully, and microholes have been completed to provide access for retrievable acoustic sensor arrays. 

Benefits
Micro-instrumentation holes potentially could cost as little as a quarter to a tenth that of conventional boreholes. Successful demonstration of a nonmetallic casing such as PVC line pipe may reduce acoustic noise and improve the performance of micro-instrumentation holes dedicated to reservoir-monitoring service. Successful demonstration of prototype drilling and completion equipment on a microdrilling system may accelerate commercialization of new products.

Project Summary
The LANL project is demonstrating the technical and economic feasibility of developing a highly mobile, self-contained, microhole drilling system for seismic data acquisition and other applications. Researchers also are evaluating commercial equipment that has the potential to enhance the performance of microdrilling. The project has completed the design of a high-pressure mud system that will support drilling mud circulation pressures up to 5,000 psi compared with the present 2,000 psi capability. High-pressure drilling will be used to evaluate a high-performance drilling assembly and increase the depth capability of the LANL coiled tubing unit from 820 feet to 1,500 feet.

Four deep micro-instrumentation wells have been drilled in Rocky Mountain Oilfield Testing Center (RMOTC) Teapot Dome field at NPR No. 3 in central Wyoming.

Quality Tubing Inc.'s QT16Cr80 stainless steel coiled tubing was used successfully as a drill stem for microdrilling.
Micro-instrumentation wells with both PVC and steel casing cemented to the surface are being evaluated by LBNL as acoustic observation wells.

(August 2005)
The LANL drilling team has completed the 4 micro-instrumentation access wells. The fourth well has been drilled to a depth of 1,310 feet LANL's coiled tubing unit will be upgraded with a new coiled tubing reel, a 1,600-foot long string of stainless steel coiled tubing, and high-pressure piping needed for evaluating drilling assembly and deeper drilling operations. A drilling permit for a 5th well is being obtained.

Publications
Thomson, J.C., and Dreesen, D.S., "Microdrilling Field Tests at RMOTC in 2004," (LA-UR-04-8578), 2004.

Thomson, J. C., "Demonstration of Microholes for Oil Production and Emplacement of Subsurface Seismic Instrumentation," (LA-UR-04-8578), 2004.

$1,300,000

$0

NETL-Rhonda Jacobs (rhonda.jacobs@netl.doe.gov or 918-699-2037)
LANL-Donald Dressen (dreesen@lanl.gov or 505-667-1913)