“一点测试法”使用原则及其在气藏产能评价中的偏差

PRINCIPLES FOR APPLICATION OF SINGLE-POINT TEST AND ERRORS OF DELIVERABILITY EVALUATION OF GAS EXPLORATION WELL

“一点测试法”在我国探井和开发井中都有着广泛的应用,其理论基础大多是基于二项式产能方程推导得来,其方程中的变量无法利用一点测试资料获得,往往是通过统计回归方法或是直接由经验方法获得α的值,特别是对于新探井,不论储层物性变化,直接采用其它气田统计回归值或经验值必将存在较大误差。文章从储层油气渗流理论出发,论述了各种产能试井的评价方法和原理,重点分析了“一点测试法”在目前气田勘探阶段产能评价中存在的问题及影响因素,最后提出了缩短测试时间的探井测试设计思想,这为储层产能测试设计、探井评价以及气井勘探开发方案编制和勘探开发部署提供了指导。

Single-point test is widely used in both exploration and development wells in China. Binomial deliverability equation is its major theoretical basis and the variables in this equation cannot be obtained by using single-point test data. The value of α is usually obtained through statistical regression or directly by using empirical methods. For new exploration wells, however, relatively large errors will occur when the values of statistical regression or empirical values of other gas fields are directly borrowed without considering variation of poroperm characteristics of reservoir. Beginning with the percolation theory of oil and gas in reservoir, various evaluation methods of deliverability testing and their principles are discussed, with focus on the problems and influential factors of application of single-point test to deliverability evaluation in gas exploration. A new design concept for deliverability testing in exploration well is presented to shorten testing time. These can guide design of deliverability testing, evaluation of exploration well, gas exploration and development planning, as well as deployment of exploration and development program.