Dewatering Systems and Techniques for Coalbed Methane Wells. Volume 1

摘要

The production of methane from most coalbeds requires the removal of the water to reduce the hydrostatic pressure and increase the relative permeability to gas flow. This study provides an evaluation of contemporary oil and gas pumping systems for this application. The systems evaluated are sucker rod (beam pumping unit), electric submersible, hydraulic jet, hydraulic piston, plunger lift, and gas lift. Ten well systems were defined to normalize the basis of comparison for the fluid-powered systems. The systems were evaluated for pumping 15 and 200 barrels per day (bpd) of water from depths of 1,000, 2,500, 4,000, and 8,000 feet. Comparisons were developed for equipment, installation, and O&M costs for each system, and combinations of systems when smaller units are used to replace initial installations later in the well life. Subjective rankings were also developed using 17 criteria to reflect individual field situations and environments.