Current well test analysis techniques are mainly based on the analysis of individual flow periods, usually the longest build-up period in the test. They provide limited reservoir information and sometimes an incorrect diagnosis of the reservoir model. In this paper, a deconvolution-based pressure buildup analysis method evolved with our deconvolution algorithms is proposed to solve the costy test issue of offshore low-permeability gas reservoirs. The proposed method utilizes short-term pressure buildup and long-term flowrate history to recover the true reservoir pressure response. The workflow for the proposed method is provided, and a synthetic case is used to verify the correctness of the method. It is shown that for fractured gas wells with 1md permeability formation, 120m fracture half-length and infinite conductivity, it takes 22 hours of buildup testing to detect the formation radial flow regime, while using the proposed method, it only takes 1 hour to finish the fracturing parameters calculation as long as production history before the test is available, which greatly saves time and cost. A field case in China East Sea is further presented to prove the feasibility of the proposed method.

well test analysis  /  fractured wells  /  deconvolution  /  pressure buildup  /  offshore low-permeability