中美致密砂岩气成藏分布异同点比较研究与意义

Comparison study on accumulation & distribution of tight sandstone gas between China and the United States and its significance

致密砂岩气已成为全球非常规天然气勘探的重点领域。中国致密砂岩气分布范围广,目前已在鄂尔多斯、四川等盆地实现了规模开发;美国落基山地区是致密砂岩气十分发育和勘探相对成熟的地区。对比研究中美致密砂岩气的形成条件和成藏特征是加快中国致密气开发利用与开拓勘探思路的有效途径。中国与美国致密气藏对比研究表明,中美致密砂岩气具有以煤系地层为主要烃源岩、储层致密、存在异常地层压力、源储紧邻与气藏大面积分布等共性特征;差异性主要体现在致密气源岩沉积环境与热演化程度,储层非均质性及其致密化因素,气藏纵向和平面分布特征等方面;控制中美致密砂岩气成藏条件和特征差异性的主要因素是沉积盆地性质、沉积环境和后期构造作用。针对中国致密砂岩气的特殊性,加强储层非均质性、优质储层预测、气藏的分布规律的研究以及加强工程技术攻关提高单井累计产量是致密砂岩气勘探开发工作的重点。

The tight gas has already been the important field of the global unconventional resource exploration. The distribution of tight gas in China is very wide; for example, the scale development of Ordos Basin and Sichuan Basin have been achieved. The Rokey Mountain in the United States is the area where the tight gas is well developed. Comparative study on the generation condition and reservoir characters of American tight gas is the use- ful way to accelerate the development of tight gas and open up the thought of exploration. The result of comparative analysis of tight gas reservoir between China and the United States shows： tight gas of China and the United States hays many common characters, for example, most source rock being coal measure strata, tight reservoir, abnormal formation pressure, resource and reservoir intimate contract and gas reservoir gross distribution and so on ; otherness is mainly reflected in tight gas source depositional environment, thermal evolution extent, reservoir heterogeneity, densifying factor, the longitudinal and plane distribution characteristics of gas reservoir. The main factors of are the character of depositional basin, sedimentary environment and deuterogene tectonic feature. In allusion to the particularity of Chinese tight gas, the key points of tight gas exploration and development are intensifying reservoir heterogeneity, high grade reservoir forecast, and the study of gas reservoir distribution and striving to make technological breakthrough to increase well cumulative production.