Abstract: New Well Testing Method for Rod Pumping Oil Wells -- Case Studies

GUOYNES, JOHN, Halliburton Energy Services

A new testing method that provides high-resolution bottomhole pressure measurement has been developed for testing rod-pumping oil wells. This new well-testing technique is conducted by running a high-resolution downhole pressure gauge assembly directly below the downhole pump. The gauge is run on the rod string without pulling completion packers or tubulars. Using the new method, a downhole pressure system is in place while the well is flowing during a well test. Downhole pressure data can then be recorded during all flow and shut-in periods of the well test, which provides more accurate reservoir data and enhanced capability for reservoir analysis.

Traditional techniques use wire-line conveyed pressure gauges, tubing-conveyed pressure recording devices, and surface pressure monitoring systems with advanced fluid-level measurement to record data. These methods are limited in capability to provide accurate test results in low-pressure conditions. The new method now allows operators of low-pressure oil wells to use advanced well test analysis software to analyze reservoir properties and skin damage.

Testing was conducted on both vertical and horizontal well completions in Niagaran oil reservoirs located in the Michigan basin. The results of the new testing process and the ensuing well test analytical results will be shown. Both vertical and horizontal wells were tested, and data retrieved from the pilot wells display excellent pressure resolution. The data from the test wells were analyzed using derivative-type curve matching and non-linear regression analytical software to validate the new pressure testing method.

The paper will compare the new well testing process with previously used rod pump testing methods. The information presented will illustrate that the new process permits more flexibility in well testing and allows for better interpretation of data in low-pressure rod pumping oil sands.

AAPG Search and Discovery Article #90911©2000 AAPG Pacific Section and Western Region Society of Petroleum Engineers, Long Beach, California