断陷型盆地温压系统与油气成藏——以伊通地堑莫里青断陷为例

The temperature-pressure systems and the oil and gas accumulation in Moliqing Sag of Yitong Graben

沉积盆地往往具有2个或2个以上的地温-地压系统,包括一个浅层的地温-地压系统及一个或一个以上的深层地温-地压系统。在同一个地温-地压系统中,地温与地层压力保持直线关系,但在不同地温-地压系统中,地温和地层压力关系的直线斜率不同。本文从地温-地压系统概念出发,分析了伊通地堑莫里青断陷的地温-地压系统特征,莫里青断陷深层和浅层存在2个叠置的地温-地压系统,其深层属于偏高压型地温-地压系统。研究还表明,莫里青断陷西部(凹陷内)双阳组为低温高压区,西北部为低温低压区,马鞍山断阶带为常温常压区,尖山断隆带为高温低压区。地温-地压系统的纵向和平面分布特征对油气藏的形成和分布有一定影响。

The depositional basin often has two or more than two temperature-pressure systems, including one temperature-pressure system of shallow-formation and one or more than one temperature-pressure systems of deep-formation. The temperature and the formation pressure keep the line relationship in the same temperature-pressure system, but in different temperature-pressure systems, the line slope of temperature-pressure relationship is different. The authors analyse Moliqing Sag＇s temperature-pressure system characters in Yitong Graben. There are two superimposed temperature-pressure systems in the shallow and deep formations of Molingqing Sag. The deep one is prone to high pressure. It is also showed that Shuangyang Group, the west of Moliqing Sag, is the low temperature and high pressure zone; the northwest is the low temperature and low pressure zone; Maanshan fault belt is the normal temperature and normal pressure zone; Jianshan uplift fault belt is the high temperature and low pressure zone. The vertical and planar distribution characters of temperature-pressure systems have some influences on the formation and distribution of petroleum pool.