SPE Member
Exxon Company, U.S.A.'s Pyote Gas Unit 14-1 in the Block 16 (Ellenburger) field became the world's deepest rod pumped well on October 7, 1983. The rod pump was installed at 16,850 ft. in an attempt to extend the productive life of the well. The artificial lift system was designed to lift wellbore fluid that was restricting the flow of gas, thus allowing the gas to be produced up the tubing-casing annulus. Implementation of the project was possible because of the recent improvements in predictive techniques, materials available for rod pumping, and industry's experience in artificial lift.
Exxon Company, U.S.A.'s Pyote Gas Unit 14-1 is a gas well in the Block 16 (Ellenburger) field located in Ward Co., Texas. This West Texas gas field, initially developed in the 1960's, produces from 17,000 ft. by depletion drive and is currently 70% depleted. The 14-1 was completed April 26, 1973 with an initial production rate of 3.8 MCFPD. As the bottom hole pressure decreased from 4500 psi to its current bottom hole pressure of 1730 psi, the gas production steadily dropped. Condensate and water could no longer production steadily dropped. Condensate and water could no longer be lifted by the gas, and fluid began to accumulate in the wellbore and near wellbore region. By June of 1983, fluid buildup had reduced production to 50 KCFPD, at which time a method of fluid removal was required to restore well productivity to recover the remaining reserves.
Enhanced gas pricing was necessary to make this project economically feasible. Once it was granted by the gas purchaser, a rod pump artificial lift system was designed and installed to restore well productivity by removing 20 BFPD from a depth of 16,850 ft. The installation of this rod pumping system required use of state-of-the-art artificial lift technology and materials.
Figures 1 and 2 illustrate the mechanical condition of Pyote Gas Unit 14-1 before the artificial lift installation. Mechanical and wellbore conditions affecting the artificial lift installation include the following:
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The wellbore was deviated less than 2 1/2 /100 f t.
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A permanent production packer was set at 13,775 f t.
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A permanently attached tailpipe below the packer had a minimum internal diameter of 2.25 in.
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The 5 in. production casing was set at 17,070 ft.
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Ellenburger perforations were from 16,294 16,944 ft.
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Flowing fluid level was located at 13,900 ft. (125 ft. below the packer)
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Static fluid level was located at 16,600 ft.
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Bottom hole temperature was 250F.
Production history suggested that, in an unloaded condition, the well should be capable of producing 500 KCFPD with less than 20 BFPD.
Mechanical, economic, and reservoir constraints determined the choice of the artificial lift system to be used on the Pyote Gas Unit 14-1. As a result of the risk involved in the installation, the following parameters were established: minimize cost, utilize an artificial lift system with a high salvage value, and minimize damage to the formation. Also, reservoir data on the well indicated the flowing fluid level was at 13,900 ft., the flowing wellhead pressure was 500 psi, and the bottom hole pressure was 1730 psi.
