基于改进的回压试井方法评价低渗气藏气井产能  

Evaluation of gas well productivity in low permeability gas reservoirs based on a modified back-pressure test method

作　　者：王晖[1] 张培军 成友友 冷有恒 郭春秋[1] 史海东[1] 魏占军 刘玲莉[1] 史立勇[1] 程木伟[1] 项红英 

机构地区：[1]中国石油勘探开发研究院 [2]中国石油(土库曼斯坦)阿姆河天然气公司 [3]西南石油大学

出　　处：《石油勘探与开发》2014年第4期453-456,共4页Petroleum Exploration and Development

基　　金：国家科技重大专项"阿姆河右岸中区天然气开发示范工程"(2011ZX05059);中国石油天然气集团公司重大专项"土库曼斯坦阿姆河右岸上产165亿方天然气开发关键技术研究与应用"(2011E-2505)

摘　　要：针对低渗气藏压力稳定时间过长的问题,结合等时试井的思路,对传统的回压试井流程进行改进,以准确评价气井产能。首先采用3~4个递增的工作制度以相同时间连续开井而不要求井底流压达到稳定,再采用一个合理的工作制度延长测试并要求井底流压及产量均达到稳定,最后关井使压力恢复至地层压力。对于改进的回压试井,如果直接套用等时试井的产能计算方法,会过大地估计生产压差而造成计算的产能偏小,因而采用流程转换-流压校正技术,将测试流程转换为等时试井,并运用压力叠加原理推导出井底流压校正方程,以解决该方法的产能计算问题。实例表明,改进的回压试井方法不仅大幅缩短了测试时间、避免了频繁开关井,而且能够保证产能的准确计算。In view of the long pressure stabilization time of low permeability gas reservoirs, the traditional backpressure test was modified based on the idea of isochronal test in order to evaluate gas well productivity accurately. Firstly, carry out continuous well startup using 3-4 incremental working systems at the same time interval without the bottom-hole flowing pressure reaching stability; then carry out a prolonged test using a reasonable working system which requires both the bottom-hole flowing pressure and the production reaching stability; finally shut in the well to allow the pressure recover to formation pressure. If the isochronal test productivity calculation method is borrowed for the modified backpressure test, the drawdown pressure will be overestimated, and calculated productivity will be underestimated. The process conversion-flowing pressure correction was used to convert the test process into an isochronal test process, and the bottom-hole flowing pressure correction equation was deduced based on pressure superposition principle to solve the productivity calculation problem with this method. The example indicates that the modified backpressure test method can not only shorten the test time significantly and avoid frequent well startup and shut-in, but also can ensure the accuracy of productivity calculation.

关 键 词：低渗气藏 井底流压 改进的回压试井 流程转换 流压校正技术 产能评价 

分 类 号：TE312[石油与天然气工程—油气田开发工程]