Summary: | The work contained in this thesis combines two previous enhanced gas recovery techniques; coproduction of water and gas from water-drive reservoirs and waterflooding of low pressure gas reservoirs. These two techniques allow the control of reservoir pressure and sweep efficiency through planed production or injection of water. A recovery optimization method, which is applicable to any gas reservoir, was developed using the concept of pressure and displacement management (PDM).
Two simulation studies were conducted, using Eclipse©, to investigate recovery optimization by coproduction and waterflooding. From the coproduction study it was determined that the water production rate needed to optimize recovery increases over time, and that accelerating production rate causes the optimum coproduction rate to increase even faster over time. In the case of the waterflooding study it was concluded that the injection rate necessary to obtain a given recovery factor in a given amount of time, with a limited injection volume goes up significantly over time, and that beginning water injection early in the life of a reservoir can have several advantages to performing a waterflood near abandonment.
In addition, a PDM computer model, that can be used for recovery analysis was developed for Excel. Although this application could be adapted to other programs, Excel allows for fast and effective screening of reservoirs amenable to PDM. Two field cases are analyzed in order to demonstrate the idea of recovery optimization and the versatility of the PDM application.
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