裂缝参数对储层渗透率和孔隙度影响实验

INFLUENCE EXPERIMENT OF THE FRACTURE PARAMETERS ON THE RESERVOIR PERMEABILITY AND POROSITY

中国致密油藏和特低渗透气藏的油气产量近年增加很快,多裂缝或缝网等大型压裂成为开采此类油气藏的重要手段。为了深入了解裂缝对油气渗流的影响,优化裂缝长度和开度等参数,以油藏工程理论为指导,以物理模拟为技术手段,开展了裂缝对致密油藏和特低渗透气藏储层渗透率和孔隙度影响实验研究。结果表明:随裂缝贯穿程度和开度增加,岩心孔隙度增大,但增幅较小;与孔隙度相比较,裂缝可明显提高岩心渗透性;当裂缝贯穿程度超过60%时,渗透率开始明显增大,当贯穿程度达到100%时,裂缝岩心渗透率要比基质岩心渗透率高10~1 000倍。

In recent years,tight oil reservoirs and extra low-permeability gas reservoirs have become the faster growing areas of the oil and gas production in China,and the large-size fracturing such as multi-crack fracturing or fracture net fracturing have developed into the main technical simulations of the reservoirs. In order to further understand the influences of the fractures on the seepage flows of the oil and gas and optimize the technological parameters such as the crack length and opening,guided by the theory of the reservoir engineering and taking the physical simulation as the technical means,the influences experimental studies were conducted for the fractures on the reservoir permeability and porosity of these kinds of the reservoirs. The achievements show that with the increase of the crack penetration degree and opening,the core porosity increases as well,but the incremental amplitude is smaller;comparing with the porosity,the fractures can obviously enhance the permeability of the core; when the crack penetration degree is more than 60%,the increase rate of the permeability increases significantly,while the degree is up to 100%,the permeability of the fractured core is higher 10-1 000 times than that of the matrix core.