一种测试油气藏岩石启动压力梯度的优化方法

An optimization method to measure rock threshold pressure gradient of oil and gas reservoirs

朱维耀 田巍 朱华银 宋智勇 孙岩

Zhu Weiyao Tian Wei Zhu Huayin Song Zhiyong Sun Yan

瞬间动用法和两端压力平衡法测定最小启动压力梯度，耗时都较长，且数据准确度不高。“压差-流量法”测试拟启动压力梯度，在定围压模式下的测试结果会偏大。基于上述分析，设计出了一体化实验流程，并制定出“非稳态动用-压力平衡法”，优选出“压差-流量法”最佳实现方式。该流程通过采用精密设备来保证测试数据的精确度，且适用各种渗透率范围岩心的测试。通过将本方法应用于吐哈油田岩心测试，测定结果符合预期，可以将该方法推广到实验室测量中。

Instantaneous threshold method and dual-ends pressure balance method are commonly used to test minimum threshold pressure gradient,but they are time-consuming and hard to ensure the accuracy of measurement data.The test results of pseudo threshold pressure may be slightly higher by using method of "differential pressure-flow" under constant confining pressure.Based on the above considerations,a set of integrated experiment process is designed,and the method of unsteady threshold-pressure balance is formulated.Also the way to implement the method of "differential pressure-flow" is optimized.The accuracy of the test results is ensured by using precise equipments in the experiment process,and the process is suitable for a wide range of core permeability test of threshold pressure gradient.Test results meet the expectation when this method is applied to well cores in Tuha oilfields,and this method can become a common measurement in the lab.

10.11743/ogg20170118