渗透率对气井产能方程及无阻流量的影响分析  

Analysis of effects of permeability on gas well productivity equation and open flow capacity

作　　者：何自新[1] 郝玉鸿[2] 

机构地区：[1]中国石油天然气股份有限公司长庆油田公司 [2]长庆油田公司勘探开发研究院

出　　处：《石油勘探与开发》2001年第5期46-48,共3页Petroleum Exploration and Development

摘　　要：基于气井二项式产能方程系数表达式的推导 ,认为在气井产能试井过程中 ,当井筒储集效应消失后 ,渗透率和影响半径只对产能方程的系数A有影响 ,系数B与它们无关 ,根据产能方程求出的无阻流量只随系数A变化。以对长庆气田陕 61井修正等时试井 (未达到拟稳态 )结果的分析为例 ,研究渗透率和影响半径对气井产能方程及无阻流量的影响 ,结论是 :①气层渗透性由气井向外围明显变好的气藏 ,渗透率和影响半径对系数A的影响小 ,压力动态基本稳定就能获得较为可靠的稳定产能方程和无阻流量 ;②气层渗透性由气井向外围变差的气藏 ,渗透率对系数A的影响较大 ,产能试井时应力求使压力动态接近或达到拟稳态 ,否则误差较大 ;③均质气藏的系数A只随影响半径变化 ,产能试井的测试过程需力求达到足够的稳定状态。Based on the derivation of the coefficient expression of the binomial eq uation of gas well productivity, the authors believe that during gas well produc tivity testing, permeability and influenced radius have effects on only the coef ficient A in the productivity equation, regardless of the coefficient B, after the well bore accumulation effect disappeared. That is, the open flow cap acity derived from the productivity equation varies upon only the coefficient A. Taking analysis of results of modified isochronal testing (not reaching the pseudo-steady state) of Well Shn-61 of Changqing gas field as an example, e ffects of permeability and influenced radius on gas well productivity equation a nd open flow capacity are studied in this paper. Conclusions are as follows: (1) For the reservoirs whose permeability becomes obviously better from well bore to the periphery, the permeability and influenced radius affect less on th e coefficient A. As long as the pressure performance is basically stable, a reliable stable productivity equation and open flow capacity are obtained; (2)Fo r the reservoirs whose permeability becomes worse from well bore to the peripher y, permeability influences obviously the coefficient A. During the gas well test for productivity, strive to make the pressure performance approach or reach the pseudo-steady state, otherwise it could make bigger errors and (3)For the homogeneous gas reservoirs, the coefficient A varies with only the influence d radius. Striving to make the testing procedure of gas well test for productivi ty reach fully steady state is necessary.

关 键 词：气层 渗透率 气井 产能方程 无阻流量 

分 类 号：TE37[石油与天然气工程—油气田开发工程] TE312