Multiple Uses For Image Logs Within The Los Angeles Basin

Elliott, J. Paul (Halliburton Energy Services) | Lockman, Dalton (Plains Exploration & Production Company) | Canady, Wyatt (Halliburton Energy Services)

OnePetro 

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 taken 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 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-six 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 accomplish the following:

  • 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 and igneous material.
At the forefront of issues addressed is the collection of reliable dip information to understand the structure and compartmentalization of new reservoirs.

Throughout the drilling program, iterative interpretations were possible as a result of reviewing data sets from each new well with the client.


INTRODUCTION

Inglewood Field History. The 1,200-acre Inglewood field was discovered in 1924 by Standard Oil of California (Chevron). The primary development focus was on the Vickers and Rindge zones at vertical depths of less than 4,000 ft. These zones are distal turbidites. They form reservoirs that are both water and gravity drainage-driven. Crude oil typically ranges between 14 and 29 degrees API gravity. Waterflooding was initiated in 1954, targeting the Vickers and Rindge zones. At the time of a seismic 3D survey in 2003, 1,400 wells had been drilled in the field, with 338 active producing wells and 142 injectors. Before kicking off the deep drilling program, the field had produced 350 million barrels of oil, with 90 percent coming from the Vickers and Rindge zones.

Stocker Resources, a predecessor company to Plains Exploration & Production Company, acquired the field in 1990. Oil and gas production had been on a gradual decline throughout the 1980s, but production rates were improved after Stocker assumed ownership and applied its ingenuity and expertise in the areas of production engineering, facilities issues, and hydrocarbon saturation mapping. Subsequent new well drilling indicated that that geologic structure was a dominant factor in accurately identifying potential areas in the reservoir with untapped reserves. Figure 1 shows the location of the Inglewood field in the Baldwin Hills area in the heart of one of the nation''s largest and most populous metropolitan areas, the Los Angeles (LA) basin.