Pioneer Natural Resources (Pioneer) operates over 2200 Coalbed Methane (CBM) wells in the Raton Basin in Colorado. Thewells produce out of two formations: the upper Raton and the lower Vermejo Formations. Many of the wells in the basin arecompleted in only one formation, with two wells on each pad; each well is completed in one of the formations. A number ofthe wells in the basin are completed in both formations and have commingled production. Pressure drawdown is critical incoalbed methane production, particularly in wells with large commingled perforation intervals; this is accomplished bylowering the gathering pressures and lowering the annular producing gas-water interface (fluid level) of the wells down belowthe perforation intervals. Pioneer uses acoustic measurement tools to determine the fluid level in the majority of the wells.However, in some of the wells, particularly the commingled wells, the acoustic tool is unable to measure the fluid level.A different method to determine the fluid level is to measure the bottom hole pressure and calculate the fluid level using adownhole pressure gauge. To test pressure gauges in the Raton basin, three wells with large perforation intervals were chosenfor a pilot test. Pioneer also chose three companies with different components for comparison. The system was designed to bedurable and mobile; it was also designed to connect to the existing production monitoring system. The installations for thethree wells were successful, though, there were two gauge failures and several pump failures. After the failures were analyzed,and the production of the wells had stabilized with the fluid below the perforations, two of the gauges were moved to otherwells. The intermittent acoustic measurements were compared with the pressure gauge information and the two trackedclosely; this increased the confidence in the acoustic measurements when values can be obtained. Several of the goals of thepilot project were achieved, including developing the successful system as planned and obtaining reliable bottom holepressures. There were additional unexpected results from the project; the failure analysis of the pumps lead to a solution forpump problems in the field, and the results provided Pioneer with a visual training tool for the field employees. It is too earlyto determine if the gauges could be used to more efficiently manage the commingled wells in the field, but a larger dataset ofwells may improve the understanding.
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