THE USE OF IMAGE LOGS TO DECIPHER COMPLEX STRUCTURES AND AID IN WELL COMPLETIONS WITHIN MATURE BASINS

摘要

The Inglewood oil field is located along the Newport-^sInglewood 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 shallow 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. During the last three years, 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:1. Resolve thrust fault geometries in the Miocene; 2. Interpret and re-map the subsurface below the Nodular Shale Unit; 3. Identify igneous body(ies) not previously recognized, by using supplemental information from conventional logs; 4. Refine the selections of intervals for perforation and stimulation within intervals of sand and igneous material. At the forefront of issues addressed is the collection of reliable dip information to understand structure and compartmentalization of new reservoirs.Throughout the drilling program, iterative interpretations were possible owing to review with the client of data sets from each new well.