利用对比技术分析吐哈盆地台北凹陷 储层孔隙特征及有效性

镜下成岩演化及孔隙类型研究结果表明,台北凹陷储层孔隙纵向上分为原生孔隙带、原生与次生孔隙混合带、次生孔隙发育带、次生孔隙减少带、二次次生孔隙发育带和二次次生孔隙减少带6种形式.结合层序地层分析,利用对比技术对各孔隙带的展布特征分析表明,储层孔隙明显分带,次生孔隙发育带整体呈现"西深东浅、南深北浅"的特征.根据现有工程技术条件,明确了储层孔隙的有效性与次生孔隙发育带关系密切,主体分布在次生孔隙发育带深部.根据台北凹陷储层物性控制因素、沉积埋藏史以及油气运移机理等特征,预测了有利勘探区,并分析了储层有效孔隙下限的控制因素,为隐蔽岩性油气藏的勘探提供基础地质依据,以降低深层勘探的投资风险.

Pore features and validity analyses of reservoir in Taibei Sag of Tuha Basin using the comparative technology

The observation of diagenetic evolution and pore types of sedimentary rock in Taibei Sag of Tuha Basin shows that the pores of reservoir in Taibei Sag can be defined vertically into six types of the primary pore zones, the primary-induced pore zones,the induced pore zones, the reduced induced pore zones, the secondary induced pore zones and the secondary reduced induced pore zones. The sequence stratigraphic and comparative analysis show that the distributions of different pore zones are obvious in vertical and horizontal directions, The plane distribution of the induced pore zones,as a whole,showed deep in the west and south parts and shallow in the east and north parts. The effectiveness of reservoir pores correlated to the induced pore zones was determined. The main pores are distributed mostly under the induced pore zones. According to the controlling factors of the reservoir properties,buried history of sedimentary, oil and gas migration, and structure characteristics, the new favorable areas for oil and gas prospecting were predicted, and the controlling factors for lower limit of effective pores in reservoir was analyzed. The results can provide basis for exploration of lithologic oil pool and depression of risk for the deep exploration.