缝洞型碳酸盐岩储集体特征及预测——以A油田PZ段为例

以A油田P_z段储集体为研究对象,采用井震联合技术进行精细连井标定可以增强层位标定横向上的连续性和可靠性。引入现代岩溶理论指导基底顶面构造解释,落实尖灭线及构造圈闭。研究区重新落实碳酸盐古潜山构造52.7 km²,增加了勘探开发的面积。利用三维可视化技术展现古地貌特征,将古地貌分为峰丛洼地、峰林谷地和古侵蚀沟3种类型。综合地质、测井和地震响应特征,将研究区储集体分为溶洞孔隙型、裂缝孔隙型和裂缝型3种类型。综合地震反演和蚂蚁体追踪建模技术,明确了研究区3类储集体的空间展布特征。认为Ⅰ类溶洞孔隙型储集体主要沿古构造高部位发育,而且位置越高储层厚度越大;Ⅱ类裂缝孔隙型储集体发育于构造斜坡部位;Ⅲ类裂缝型储集体受断裂影响明显,发育于断裂附近。

Characteristics and prediction of fracture-vug carbonate reservoirs -an example of Pz layer in A oilfield

This paper studied the reservoir of Pz layer in A oilfield.Fine cross-well calibration by using the technique of log-seismic integration can improve the lateral continuity and reliability of stratigraphic correlation.Modern karst patterns were introduced to guide basement top structure interpretation,and to delineate pinch-out line and structural trap.The newly found buried hill structure is 52.7 km2,which increase the exploration area.We divided the palaeogeomorphology into peak-cluster depression,peak forest valley and paleo-erosive gulley with 3D visualization technique.Based on integration of geologic data,logging data and seismic response,we divided the reservoirs into three types including cavern-pore fracture-pore and fracture types.We delineated the distribution of the reservoirs through seismic inversion and ant tracking modeling.Type Ⅰ reservoirs(i.e.cavern-pore type) mainly occur on paleo-structure highs and their thickness enlarge along with their increasing height.Type Ⅱ reservoirs(i.e.fracture-pore type) distribute at the slope of the structure.Type Ⅲ reservoirs(i.e.fracture type) occur near faults,thus are significantly affected by the faults.