预加压测试页岩含气量新方法

发布时间：2018-04-22 17:19

本文选题：页岩 + 含气量　；参考：《石油学报》2017年10期

【摘要】：页岩含气量是页岩气藏储量计算的重要参数,对气藏评价和开发指标计算有重要意义。现场解吸是测试页岩含气量的主要方法,但由于损失气量占含气量的40%~80%,使传统方法的测试结果饱受质疑。结合国内外新的测试方法,提出了一种预加压测试页岩含气量的新方法,可以规避损失气量的计算,大幅度提高测试精度。在井场,将岩心置于高压罐内,用增压泵将甲烷注入岩心直至压力达到预定压力,在储层温度下,待压力稳定后解吸测试页岩含气量。该方法对于是否已知储层压力的不同情况,采取不同的测试流程。如果已知储层压力,预加压使岩心压力达到储层压力,解吸结果就是页岩含气量;如果储层压力未知,则可通过建立页岩含气量计算理论公式求解。测试流程为先对1个岩心开展超过吸附饱和压力的2次加压(压力均超过20 MPa)及解吸测试,然后利用理论公式和2次加压解吸结果,得到单位质量页岩内的吸附气量和任意压力下的游离气量计算公式。在后期测试出储层压力后,根据游离气计算公式,计算出该压力下的游离气量,游离气量与吸附气量之和即为页岩的含气量。
[Abstract]:Shale gas content is an important parameter in the calculation of shale gas reservoir reserves, which is of great significance to gas reservoir evaluation and development index calculation. On-site desorption is the main method to test shale gas content, but because the gas loss accounts for 40% of the gas content, the test results of the traditional method have been questioned. Combined with new testing methods at home and abroad, a new method of pre-pressurized shale gas content measurement is proposed, which can avoid the calculation of gas loss and greatly improve the accuracy of the test. At the well site, the core is placed in a high pressure tank, and methane is injected into the core with a booster pump until the pressure reaches a predetermined pressure. At the reservoir temperature, the shale gas content is desorbed and tested after the pressure is stable. The method adopts different testing procedures for different conditions of known reservoir pressure. If the reservoir pressure is known, the core pressure can reach the reservoir pressure, the desorption result is shale gas content, and if the reservoir pressure is unknown, the theoretical formula of shale gas content calculation can be established. The test procedure is to carry out two times of pressure (pressure over 20 MPA) and desorption test for one core, and then use the theoretical formula and the results of twice pressure desorption. The formula for calculating the amount of adsorbed gas in shale and free gas under arbitrary pressure is obtained. After testing the reservoir pressure in the later stage, according to the formula of free gas, the amount of free gas under the pressure is calculated. The sum of free gas and adsorption gas is the gas content of shale.
【作者单位】：重庆矿产资源开发有限公司;中国石油勘探开发研究院廊坊分院;
【基金】：国家重大科技专项(2011ZX05018-005)资助
【分类号】：P618.13

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