大牛地气田下古生界致密碳酸盐岩体积酸压试验

大牛地气田下古生界储层是典型的致密碳酸盐岩储层,水平井投产后产量递减较快,稳产难度大,因此如何提高改造体积和压裂后产量,实现较长时期的稳产,是本次试验的目的.本文从岩石脆性指数、天然裂缝发育状况、体积压裂所需的岩石力学特征及储层岩石矿物组分等四个方面分析了大牛地气田下古生界碳酸盐岩储层实施体积压裂的可行性.结果表明:大...

Volumetric acid pressure test of dense carbonate rocks in the lower paleozoic of Daniudi gasfield

The Daniudi gasfield of lower paleozoic is a typical compact carbonate reservoir.The production after the commissioning of horizontal well declines fast and production stabilization is of high difficulty.Therefore,how to further improve the volume of the reform and the post-pressing output to achieve stable production is the purpose of this test.The feasibility of volume fracturing in lower paleozoic carbonate reservoirs in Daniudi gasfield is analyzed from four aspects,rock brittleness index,natural fracture development,rock mechanics characteristics required for volume fracturing and rock mineral composition of reservoirs.The results show that the brittleness index of lower paleozoic carbonate reservoir in Daniudi gasfield is 0.36~0.68.The proportion of unfilled cracks reached 28.4%,and natural fractures are relatively developed.Poisson's ratio is 0.20~0.24,Young's modulus is 27~32 GPa,the quartz content of rocks is 0.6%~1.1%,and calcite content Up to 98%,the condition of crack propagation in complex fractures of volume fracturing can be satisfied.Field experiments show that volumetric acid pressure has good applicability and significant transformation effect in the lower paleozoic carbonate tight reservoir in Daniudi gasfield,which can be an important measure for the efficient development of such reservoirs.