Mobil has established "Reservoir Management Teams" (RMT) to evaluate and manage major fields. Core team members include a reservoir engineer, production geologists, operations engineer and the operating field foreman. These teams have found that many of the older gas reservoirs were produced to depletion based on the economics at the time of production. Wells were abandoned or recompleted when unable to produce into the 1000 psig (6.89 MPa) line pressure. Others were abandoned for the same reasons at pressures as low as 300 psi (2.07 MPa). The sandstone reservoir completions were usually not stimulated. Fluid blocks caused several premature abandonments. Gas reservoirs got less geological attention than oil reservoirs. Multiple layers were commingled into one zone of completion with some pay left unperforated. Wide well spacing and poor completion practices resulted in bypassing gas reserves in some older fields.
As a result of the above practices, the RMT's have proved that a considerable amount of gas reserves may be recoverable from some of these "depleted" reservoirs. Low BHP reservoirs will need compression, but many of the older fields have a low pressure gathering system in place. However, to recover these reserves, it will be required to successfully complete both old and new wells in reservoirs from 6000–7000 foot (1828–2133 m) with only 300 psi (2.07 MPa) bottom-hole pressure (BHP) or lower. The completion and stimulation procedures needed to successfully complete these very low BHP gas wells require technical expertise along with a large measure of patience. This paper will attempt to illustrate the theory and the techniques used to accomplish very low BHP completions.