Multiple Uses of Image Logs Within the Los Angeles Basin

Paul Elliott¹, Dalton Lockman², and Thomas Howard^1
1Halliburton, 3000 N. Sam Houston Parkway E. J2T23, Houston, TX 77032
²Plains Exploration and Production Company, 1200 Discovery Drive #500, Bakersfield, CA 93309

The Inglewood oil field is located along the Newport-Inglewood Fault trend of the Los Angeles Basin, California. The field has undergone several phases of development since its discovery in 1924. The field’s initial development was based solely on drilling topographic highs and establishing production mostly from the Pliocene zones where the geologic structure was more fully understood. Geologic data during the first 70 years of production consisted of formation tops identified from well logs, from wells that were drilled to the Pliocene through upper Miocene. From 2003 to 2006, older, middle Miocene zones have been the target of new development. Results from recently drilled wells indicate that geologic structure is still a dominant factor in accurately understanding and identifying deeper zones in the field with new reserves. These lower zones are structurally complex reservoirs that present challenges both in characterization and subsequent development. Thirty of forty development wells into the lower most zones have been logged with conventional triple combo openhole logging suites and electrical micro image logs. Information from the image logs has been used to:

•      Resolve thrust fault geometries in the Miocene
•      Interpret and re-map the subsurface below the Nodular Shale Unit
•      Identify igneous units not distinguishable on conventional logs
•      Provide fracture characterization used for successfully completing within igneous units
•      Refine the selections of intervals for perforation and frac stimulation within intervals of sand

At the forefront of issues addressed is the collection of reliable dip information in order to understand structure and compartmentalization of new reservoirs, and determination of “image facies” to identify and characterize the igneous units.

AAPG Search and Discovery Article #90076©2008 AAPG Pacific Section, Bakersfield, California