塔里木盆地大宛齐油田康村组储层特征及评价

在地层对比的基础上，深入研究了大宛齐油田康村组储层的岩石学特征、储集砂体成因类型及其特征、储层孔隙类型、孔隙结构特征及储层分布规律。大宛齐油田康村组属于低弯度河进入极浅水湖泊形成的三角洲沉积体系，决定了它主要的储集砂体成因类型为三角洲砂体，其中又可细分为三角洲平原分流河道砂体、三角洲前缘水下分流河道砂体和河口砂坝砂体，主要储集空间类型是剩余原生粒间孔隙，其次是粒间溶孔和微孔隙。分流河道砂体以粒度较粗的中粗砂岩、含砾砂岩和细砂岩为主，发育大孔隙，粗喉道，孔隙度大，渗透率高，储集性能好；河口砂坝砂体，粒度相对较细，以细-粉砂岩为主，孔隙度相对较低，孔径也相对较小。纵向上，康村组中下部砂体较发育，上部次之，以砂泥互层形式叠置，但总体上砂岩含量不高，一般在15％～30％之间；康村组储层横向分布受物源等因素影响，呈现出东北部厚、西北部薄的特点。储层物性总的分布规律是由北东往南西方向，孔隙度减小，由南东往北西方向渗透率变差。

RESERVOIR CHARACTERISTICS AND EVALUATION OF THE KANGCUN FORMATION IN THE DAWANQI OILFIELD,TARIM BASIN

On the basis of stratigraphic correlation, the characteristics of reservoir rocks of the Kangcun Formation, origin, types and features of sand bodies, pore types and textures of reservoir rocks and distribution characteristics of the reservoir in the Dawanqi oilfield have been intensively studies. The Kangcun Formation of the Dawan oilfield belongs to a delta sedimentary system formed when a river with a low meandering curvature enters a very shallow lake, which determines that its main reservoir sand bodies are of deltaic sand body type. The sand bodies may be subdivided into delta plain distributary channel sand bodies, delta-front subaqueous distributary channel sand bodies and river mouth bar sand bodies. The main reservoir space types are residual primary intergranular pores and next come intergranular solution pores and micropores. The distributary channel sand bodies consist predominantly of medium and coarse sandstone, pebbly sandstone and fine sandstone, which are characterized by development of large pores and throats, high porosity and permeability and good accumulation properties, and the river mouth bar sand bodies are composed chiefly of fine sandstone and siltstone with a relatively fine grain size, a relatively low porosity, a high permeability and a relatively small pore diameter. Vertically, sand bodies are better developed in the middle and lower parts of the Kangcun Formation and less developed in the upper part, where arenaceous beds and argillaceous beds alternate with each other but generally the sandstone content is not high, commonly ranging from 15 to 30%. Laterally, due to the influence of factors such as provenance, the Kangcun Formation reservoir is thick in the northeast and thin in the northwest. The general distribution pattern of the physical properties of the reservoir is that: the porosity decreases from northeast to southwest and the permeability becomes poor from southeast to northwest.