超高压气藏天然气拟对比压缩系数的数值解法  

Numerical Solution of Ultra-high Gas Reservoir Pseudo-reduced Compressibility

作　　者：袁义东[1] 张金功[1] 仝可佳 刘林玉[1] 刘艳妮[3] 孟庆安 王卓[1] 李建新 Yuan Yidong;Zhang Jingong;Tong Kejia;Liu Linyu;Liu Yanni;Meng Qing＇an;Wang Zhuo;Li Jianxin(Department of Geology,Northwest University,Xi＇an 710069,China;Research Institute of Exploration and Development of Tarim Oilfield,PetroChina,Korla Xinjiang 841000,China;Research Institute of Exploration and Development of Changqing Oilfield,PetroChina,Xi＇an 710018,China;Shengli Petroleum Engineering Co.Ltd.Drilling and Technology Company of SINOPEC,Dongying Shandong 257064,China)

机构地区：[1]西北大学地质学系,西安710069 [2]中国石油塔里木油田分公司勘探开发研究院,新疆库尔勒841000 [3]中国石油长庆油田分公司勘探开发研究院,西安710018 [4]胜利石油工程有限公司钻井工程技术公司,山东东营257064

出　　处：《地质科技情报》2018年第4期190-195,共6页Geological Science and Technology Information

基　　金：国家科技重大专项课题(2017ZX05009-002)

摘　　要：快速准确地获取超高压气藏天然气藏流体压缩系数是一个备受关注的问题。塔里木油田M超高压气藏的测试实例证实了DAK、DPR及HY 3种方法计算偏差因子的可靠性,在此基础上使用一阶中心差分算法计算了该气藏的天然气压缩系数。与Trube图版的对比表明,DPR方法的计算结果具有最高的精度,推荐数值计算时采用。数值实验结果表明,Tpr(拟对比温度)大于1.2时计算精度较高且与差分步长无关,相对误差小于5%;Tpr小于1.2时不建议使用数值方法。在借鉴部分超高压天然气偏差因子研究基础上,拓展了Trube图版的使用范围,将拟对比压力Ppr应用范围从15扩大到30,Tpr应用范围从2.0扩大到3.0,并重绘了图版。研究结果对超高压气藏的相关研究具有一定的理论参考和实际应用意义。Natural gas Isothermal Compressibility Factor（ICF）is of vital importance to gas reservoir engineering,and generally,it was obtained by laboratory PVTtests or refers to Trube charts,which is the relationship between gas Pseudo-reduced Pressure（Ppr）and Pseudo-reduced Temperature（Tpr）with gas ICF.However,the tests are so time and money consuming,and the range of charts is so narrowed that it can hardly completely meet the special demands of ultra-high pressure gas reservoir study.Therefore,time and precision are the key issue to gas engineers,especially for those who work for ultra-high pressure gas reservoirs.In this study,mathematical calculation tests are applied to find the new way to get those parameters more quickly and precisely.The example of M dry gas reservoir,Tarim Oilfield,shows that the Maximum Relative Errors（RE）of DAK,DPR and HY calculating results of measured deviated factor is less than 5% and so is reliable for engineering calculation.Meanwhile the calculated ICF is obtained by using one step central difference algorithm of DAK,DPR and HY.Error analysis inferred that results of DPR method have the highest precision and thus should be recommended for mathematical calculation.Also,the test inferred that the RE between calculated data by DPR method and digitized Turbe charts is less than 5% when Tpris larger than 1.2 and the results are more reliable than Tprless than 1.2.In addition,influence of difference step to calculation result is also tested as calculation step is 0.001,0.01,0.1 and 0.5 respectively.The test also pointed out the results are unrelated to difference step when Tpris larger than 1.2 and the recommended calculation step is 0.1.Based on parts of the study on deviated factor in ultra-high pressure reservoirs,the Trube charts are recalculated and redrawn when Ppris enlarged from 15 to 30,and Tpris enlarged from 2.0 to 3.0,respectively.This may have some theoretical and practical value for the study of ultra-high pressure gas reservoir.

关 键 词：拟对比压缩系数 等温压缩系数 Trube图版 数值解法 天然气 超高压气藏 

分 类 号：TE318[石油与天然气工程—油气田开发工程]