塔中地区良里塔格组连续型碳酸盐岩油气藏地质特征与成因机制

根据102口探井油气测试数据以及测井、录井、岩心等资料,并结合区域地质背景和典型油气藏剖析,塔中地区良里塔格组碳酸盐岩油气藏具有储层整体致密、甜点局部发育、目的层叠置连片、油气广泛分布4大地质特征.源-储大面积紧密接触是油气近源充注机制的基础,控制了油气纵向叠置发育;断裂带是储层局部高孔渗分布的关键,控制了油气的局部高产富集;盖层普遍发育为油气藏保存提供条件,控制了油气平面广泛连片分布.综合研究表明,塔中地区良里塔格组油气藏油气来源于多套烃源岩,经过多期成藏与构造调整改造,属于构造调整改造作用下形成的叠复连续型油气藏.

Geological features and formation mechanism of successive-type carbonate hydrocarbon reservoirs in Lianglitage Formation of Tazhong area

Based on hydrocarbon test, well logging, mud logging and core data of 102 wells, in combination with regional geological background and typical hydrocarbon reservoir analysis, four geologic features are found in carbonate hydrocarbon reservoir in Lianglitage Formation of Tazhong area, i.e., tight reservoir, local development of sweet-spot, superimposed sheets of target strata, and wide hydrocarbon distribution. The large-scale close contact between source rocks and reservoirs provides a basis for near-source filling mechanism, and controls vertically superimposed development of hydrocarbons; fault belt is the key for local distribution of high-porosity and high-permeability reservoirs, and controls high yield and enrichment of oil and gas; wide development of caprock allows hydrocarbons storage, and controls wide and sheet-like distribution of hydrocarbons on the horizontal level. Comprehensive research suggests that hydrocarbon in Lianglitage reservoirs of Tazhong area are originated from many sets of source rocks, and reservoirs belongs to superimposed and successive type formed though multi-phase hydrocarbon accumulation as well as structural adjustment and transformation.