Flow Description of Gas Well in Basement Granite Reservoir from Well Test Analysis
Hari K. Oetomo, Ratnayu Sitaresmi, Dimas Panji Laksana
Universitas Trisakti
Abstract
A sweet gas exploration well, penetrating 3286 feet thickness of Granite Basement with 70 feet thickness of extensive fracture was tested. Initial step was to study all geologycal and petrophysical aspects of reservoir and well . These data were used to obtain the sense of reservoir shape model and its fracture flow behavior. Interpreting the log gives the presents of partial fracture and open fracture, which are shown in the early time region as a fracture dominated flow and very small wellbore storage effect. The bilinear flow before middle time region and followed by two porosity fracture model at middle time region are shown afterward. Constant pressure circle boundary is shown in the late time period. In summarized, the well flow model is in infinite acting conductivity with two porosity pseudo steady state reservoir model and constant pressure circle boundary. The permeability is 1.45 mD, with -0.52 skin and 1962 Psia reservoir pressure; meanwhile the fracture coefficient is 50 mD-ft, storativity is 0.51, and interporosity flow coefficient is 4.38x10-6 mD-ft. All well and reservoir data pertaining well test is very important for getting a reliable well test interpretation result; to get better understanding reservoir flow behavior.
Keywords: Pressure Build Up Test, Pressure Derivative, Granite Basement, Sweet Gas Well,
Topic: Industry Engineering