Simulation on the Dynamic Variation of Properties During Deflagration Fracturing in Screen Completed Well

A deflagration fracturing technique, also referred to as high-energy gas fracturing (HEGF), was used to create several fractures radiating from a wellbore to improve reservoir conductivity. Theoretical studies of deflagration fracturing were mainly focused on open-hole or perforated well completions. In this study, the deflagration fracturing technique was used in a screen completed well because conductivity was enhanced in a variety of reservoir types. A simulation on the dynamic variation of gas pressure in a screen completed well was required to avoid destroying the tool because of the structural difference between the screen pipe and casing pipe. A model was built to describe the deflagration fracturing process in a screen completed well. The equation for fluid flowing through screened pipe was introduced along with the traditional equations for perforated wells. Then, a numerical simulation was run to validate the equations. The simulated accuracy approached 80% when compared to the real production-increasing ratio. The simulated maximum pressure was 50.3 MPa with safe parameters for a screen completed well. The maximum length of a symmetric semi-fracture was 4.18 m, and the maximum width was 5.47 mm. The maximum gas pressure was lower for a higher density of holes and larger screen pipe size. Results of the simulations can be used to choose proper screen pipe for deflagration fracturing.