塔里木盆地库车坳陷北部构造带中东段中下侏罗统砂体特征及油气勘探意义

塔里木盆地库车坳陷北部构造带侏罗系是“十三五”油气勘探的重点接替领域，根据全国第四次资源评价，该带具有5.65×10⁸t油气当量的资源量，但资源探明程度只有3.7%。为明确中下侏罗统的勘探方向、有利区带和圈闭类型，开展了基于露头、钻井及测井资料的沉积微相及砂体构型研究。明确了中下侏罗统发育宽缓湖盆湖侵背景下的辫状河三角洲平原—前缘—滨浅湖沉积体系，其中阿合组沉积辫状河三角洲上平原大型辫状河道巨厚砂体，阳霞组、克孜勒努尔组沉积辫状河三角洲下平原—前缘中小型河道中薄层砂体。建立了3种有利成藏的砂体建筑模型，提出了阿合组辫状河三角洲平原上河道垂向加积砂体是构造油气藏勘探领域；阳霞组辫状河三角洲平原下河道横向叠瓦状砂体和克孜勒努尔组前缘水道侧积透镜状砂体是构造—岩性、岩性油气藏勘探领域。吐格尔明背斜东、北及西翼部克孜勒努尔组和阳霞组构造—岩性油气藏最有利，优选了构造翼部有利面积700km²。迪北斜坡带平台区构造油气藏最有利，阿合组储层孔隙度平均为5.6%，渗透率平均为0.75×10^-3μm²，有利面积可达750km²。为北部构造带中东段中下侏罗统优选有利方向和油气圈闭勘探类型提供了可靠证据。

The sandstone characteristics and hydrocarbon exploration signification of Lower Jurassic in middle east section of northern tectonic belt in Kuqa Depression,Tarim Basin

Jurassic of northern structural belt in Kuqa is “the 13^th five-year plan” oil and gas exploration areas of focus to replace, according to national fourth time resource evaluation, the belt has a 565 million tons of oil equivalent of resources, but the resources to carry out the degree of only 3.7%. In order to clarify the exploration direction, favorable zone and trap type of the Middle and Lower Jurassic, a study on sedimentary microfacies and sand body configuration based on outcrop, drilling and logging is carried out. This paper clarified that the Middle-Lower Jurassic develops braided river delta plain-front-shore and shallow lake sedimentary system under the lacustrine invasion background of wide and gentle lake basin, among which the Ahe Formation deposited large scale braided channel giant sand body of the braided river delta upper plain, and Yangxia and Kezilenur Formations deposited medium-small channel medium-thin layer sand body of the lower plain-front of the braided river delta. In this paper, three kinds of sand body building models are established, and the vertical accretion sand body in the upper plain of the Ahe Formation is constructed. In the lower plain of Yangxia Formation, the transverse sand body of the river and the lateral channel of the leading edge of the Kezilenur are tectonic - lithology and lithologic oil and gas reservoir. It is advantageous to construct lithologic oil and gas reservoirs in the low-amplitude tectonic zone in the east, north and west wing of Tugeerming. The lithologic oil and gas reservoirs are second in the tectonic wing. The optimum area of the construction wing area is 700km².The structure of the platform area of the Dibei slope zone is the most favorable. The porosity of the reservoir is 5.6%, with an average permeability of 0.75×10^-3μm² and a favorable area of 750km². It provides reliable basis for the selection of favorable direction for the Middle-Lower Jurassic in the middle east section of the northern tectonic belt and the tectonic and lithological reservoirs in the large ancient uplift and slope background.