桑塔木油气藏相态的综合判断

COMPREHENSIVE DETERMINATION OF PHASES IN STM OIL AND GAS POOLPU

蒲仁海 郑冰 蔡其新

PU Ren-hai ZHENG Bing CAI Qi-xin

西北大学地质系, 陕西西安 710069 2. 中国石化无锡实验地质研究所, 江苏无锡 214151

Department of Geology, Northwest University, Xi'an, Shaanxi 710069, China 2. Wuxi Research Institute of Experimental Geology, SINOPEC, Wuxi, Jiangsu 214151, China

塔里木盆地北部三叠系STM低幅度构造油气藏,是一个具底水的油气同产的凝析油气藏,其地下为凝析气相、还是气液两相,由于缺乏高压取样测试资料而难以确认。前人据其所产油气性质和气油比判断为凝析气相,但发现井沙29井中油组厚7m的油气层在声波测井曲线上却无明显的高时差响应。相态判断对该油气藏评价、储量计算、开发方案部署等影响很大,作者从物理性质、气油比、组分Z值法、Φ值法、因子判别法、测井解释、气层低频地震响应正演模型及其在构造图上圈闭顶部低频范围与对应深度上测井响应的吻合性等7种方法的综合分析,认为中油组为具凝析气顶和油环的油气藏。这一认识被后来所钻沙51井证实。

The Triassic low-relief structural STM oil and gas pool in the North Tarim Basin is a condensate oil and gas pool with bottom water which produces oil and gas simultaneously.But it is difficult to determine whether it is condensate gas phase or binary phases of gas and liquid underground for lack of high pressure sampling and testing data. Predecessors judged it as condensate gas phase according to hydrocarbon features and the ratio of gas and oil.But it was found that the reservoir with 7m thick middle oil formation in discovery well Sha 29 had no obvious high-moveout responses in acoustic logging curves. The determination of phases has great influence on the evaluation,reverse caluation and development planning of the oil and gas pool.Comprehensive using the physical properties,the ratio of gas and oil,the method of component Z values,the method of Φ values,the method of factor determination,the method of well logging interpretation,the positive model of low frequency seismic responses in gas formation and its coincidence with logging responses within low-frequency ranges and at corresponding depths on the top of traps in structural maps,it is considered that the middle oil formation is an oil and gas pool with condensate gas tops and oil rings.This is proved by well Sha 51 drilled later.

https://doi.org/10.11781/sysydz200102178