基于地层测试技术的裂缝性火山岩储层敏感性研究

Study on the Sensitivity of Fractured Volcanic Reservoirs by Formation Testing Technology

准噶尔盆地中拐凸起火山岩储层裂缝发育,储层顶部有良好的泥岩盖层,改造后均能获得较高产量,但对xx20井实施压裂改造后,产能与预期差异大。目前常规实验方法无法对裂缝性火山岩储层进行有效的敏感性评价,为查明中拐凸起石炭系裂缝性火山岩储层敏感性,利用多流地层测试技术通过多次开、关井,了解了生产压差、外来流体对表皮系数、渗透率等参数的变化特征,探索性评价储层的敏感性,并选取"井储+表皮+均质无限大地层"模型分析了测试数据,测试结果表明:加大抽汲生产压差,对井周污染带的改善不明显,该储层对压力敏感性较小。地层测试技术能够反映出压裂液在火山岩裂缝储层的敏感性特征,为非常规储层的敏感性动态评价提供新思路,对裂缝性、低渗储层的敏感性评价具有一定的借鉴意义。

The volcanic reservoir of Zhongguai uplift in Junggar basin is characterized by well developed fractures and good mudstone caprock at the top of the reservoir. After reformation, higher production can be obtained. However, after fracturing of well XX 20, there was large difference in production capacity from expectation. At present, conventional experimental methods cannot effectively evaluate the sensitivity of fractured volcanic reservoirs. In order to find out the sensitivity of carboniferous fractured volcanic reservoirs in Zhongguai uplift, multi-flow formation testing technology was used to understand the variation characteristics of production pressure difference, skin factor, permeability and other parameters by opening and closing the well, and the sensitivity of reservoirs was evaluated.The model of "well storage + skin + homogeneous infinite formation" was used to analyze the test data. The test results showed that the improvement of the contaminated zone around the well was not obvious by increasing the pressure difference of swabbing production, and the reservoir was less sensitive to pressure. Formation testing technology can reflect the sensitivity characteristics of fracturing fluid in volcanic fractured reservoirs, providing a new idea for dynamic evaluation of unconventional reservoir sensitivity, and having certain reference significance for sensitivity evaluation of fractured and low permeability reservoirs.