Introduction

Recent oil and gas property trade involving multi-reservoir fields have required that studies be made within stringent time limitations. The evaluation of these fields has necessitated the evolving of a streamlined method of gathering, cataloguing, processing, and interpreting the basic geologic and engineering data. Methods are herein outlined for the rapid processing of such data and for the preparation of structure and thickness maps suitable for the engineer's use in estimating reserves, in predicting reservoir performance, in determining development of the field for optimum primary and secondary recoveries, and establishing the bases for optimum future operating methods.

TIME AND BUDGET SCHEDULE

Before a study is undertaken, the geologist is often required to submit a budget estimate and a provisional time schedule covering the geological part of a reservoir study.

CATALOGUING AND CHECKING

The geologist's role in expediting the engineer's work in evaluating a single or multipay field starts immediately with the arrival of all of the client's available information. The mass of data received from the client must be checked in and catalogued. This is generally handled by a secretary-technician, referred to in this paper as a statistician. The geologist aids in segregating material which can be transmitted immediately to the engineers and that which is essential or useful for preparing the necessary geological maps for the engineer's use. The material is then checked against a gathering data list comprised of most of the items listed below, and any missing items are ordered.

DATA ROUTING

Engineers: The engineers are generally given the following items immediately:

  1. Copy of the schedule of lease and wells.

  2. A preliminary work copy of a well and lease location map.

  3. Schedule of income and expense interests.

  4. Schedule of oil and gas prices and trucking charges.

  5. Schedule of operating expenses and ad valoremtaxes.

  6. Core descriptions, copy of core data, and special core analysis reports.

  7. Fluid data including fluid sample analyses, surface fluid sample data, GPM tests, gas analyses, and water analyses.

  8. Production data-oil, water, and gas by leases and/or wells by months.

  9. Special well tests on oil wells, deliverability tests on gas wells, GOR and watercut tests.

  10. History of reservoir performance including data and curves of BHP, GOR, and rates vs. cumulative production.

  11. Any engineering committee reports, reports on reservoir studies, outside consultant reports, and MER data.

All the foregoing data will permit the engineers to start their tabulations and studies simultaneously with the geological section.

Geologists:The geological basic data generally includes the following:

  1. Schedule of leases and wells.

  2. Maps and location plots, including client'sstructure and isopach maps.

  3. Client's cross sections and regional data.

  4. Logs (electrical, sonic, induction, micro, gammaray-neutron) and completion cards.

  5. Well completion data, including DST data, mechanical data, and other significant well file data.

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