苏里格气田优质储层的控制因素

RESEARCH ON THE BASIC CHARACTERISTICS AND CONTROL FACTORS OF HIGH-QUALITY RESERVOIR IN SULIGE GAS FIELD

苏里格气田优质储层具有埋藏深度大、深埋时间长、成岩演化阶段高、物性好的特点。该套储层的分布主要受沉积环境、石英含量、颗粒粒度、埋藏史、成岩作用、裂缝发育程度、异常高压等因素的控制。其中分流河道为最有利的微相 ;石英含量大于 90 %、特别是大于 95 %时 ,孔渗明显变好 ;孔隙度大于 8%、渗透率大于 0 .5×10 -3 μm2 的样品通常分布于粒度中值在 0 .5 0mm以上的粗砂岩中 ;裂缝对储层物性有较大的改善 ;异常高压对优质储层的发育具有一定的保护作用 ,应特别加强对裂缝的研究。

The reservoir in Sulige Ras field is of these characteristics, such as great burial depth, long deep-burial time, high diagenetic evolution stages and good petrophysical property. The distribution of high-quality reservoir is controlled by the factors as sedimentary environment, quartz content, grain size, burial history, diagcnesis, fracture-developed degree and abnormal high formation pressure, etc. It is concluded that the distributary channel is the most favourable microfacies: the porosity and permeability become better obviouly when the quartz content is more than 90%, especially over 95%: the samples which porosity is more than 8% and permeability more than 0.5 × 10-3μm2 are generally distributed in the coarse sand-stones with grain size mid-value of above 0. 50 mm: fractures can greatly improve the petrophysical property i and the abnormal high formation pressures played a preservation role in the development of the high-quality reservoir, so that the research on fractures should be specially strengthened.