Study On Fracture Mechanism Of Tight Sandstone By High Temperature Electric Heating

Tight sandstone gas reservoir has dense rocks and small internal pores,which are prone to water lock damage and severely restrict gas well productivity.Therefore put forward by means of high temperature electric heating water lock,and improve the environment of reservoir seepage,but high temperature crack mechanism is unclear,according to the above problem,this paper combined with the theoretical research,experiment and computer simulation,established the dense sandstone week of well temperature field,temperature,time,heating mode on the influence of cracks,the tight sandstone circumferential stress distribution were studied under the environment of high temperature well,from the macro and micro,experiment and simulation of multiple perspectives reveals the mechanism of high temperature electric heating compacted sandstone crack,provide scientific support for downhole electric heating technology,the main results were as follows:(1)According to the classical heat transfer equation,the peripheral temperature field of tight sandstone Wells was established,and through computer simulation,the heating radius of downhole electric heating was about 1.2m,and its sensitivity was analyzed.(2)High temperature electrical heating can improve the percolation environment and permeability of the reservoir,and the temperature gradient has a great influence on the permeability of the reservoir.The closer to the well,the better the heating effect is,and the better the fracturing effect is on tight sandstone.(3)In different temperature,different heating time and heating mode,with the increase of time,under 1000?,fracture development conditions improved significantly,and communicate with each other to form seepage network,at about 1200?,due to rock glaze phenomenon occurs,so the seepage situation changed little,heating can control the temperature at about 1000?.(4)Based on the stress simulation analysis of actual strata,the stress cloud maps under different heating temperatures and heating durations were obtained,and the fracture strength of each point at the radial distance of strata was analyzed according to the mole-coulomb criterion,so as to provide theoretical basis for subsequent engineering practice.