安塞油田坪桥水平井区沉积微相三维建模研究

以安塞油田坪桥水平井区为例,探讨了应用水平井和露头资料及标点过程(示性点过程)方法进行沉积微相三维建模的思路与方法,同时对研究区三角洲前缘分流河道的定量结构模式进行了深入的研究。研究表明,坪桥水平井区三角洲分流河道单砂体宽度一般为40～100m左右。砂体结构呈两种模式,其一为“迷宫状”,砂体离散地分布于湖相泥岩中,其二为“拼合板状”,多个砂体在侧向上叠置而形成连片分布的砂体,但部分单砂体间可被泥质或钙质薄层侧积层所隔挡。应用水平井资料和露头资料,可有效地提取三维建模所必须的地质统计学参数。研究表明,采用标点过程方法,可建立符合地质实际的沉积微相三维模型。

3D Microfacies Modeling of Pingqiao Horizontal Well Region of Ansai Oilfield

Taking the Pingqiao horizontal well region of Ansai oil-field as an example, this paper deals with the method of 3D modeling of sedimentary microfacies using horizontal well and outcrop data and Marked Point Processes technique, in addition deeply study the quantitative architecture model of the delta front in study area. The oil-bearing strata of the study area is Chang 61 1 of Triassic Yanchang Formation, 20 m or so in thickness. The microfacies is distributary channel, splay and inter-channel shale. There are 10 vertical wells and 5 horizontal wells in the study area in addition to nearby outcrop. Research shows that the width of single channel sandbody is generally from 40 m to 100 m, smaller than the distance among vertical wells. There exist two kinds of reservoir architecture. One is labyrinth reservoir architecture, in which narrow and lenticular sand bodies are distributed discretely within lacustrine shale. The other is jigsaw-puzzle reservoir architecture, which consists of a series of channel sand bodies that laterally overlapped to continuous sandbodies, in which some lateral shaly or calcite non permeable barriers exist among single sandbodies. Geostatistical parameters for 3D microfacies modeling can be picked up effectively using horizontal well and nearby outcrop data. Research shows that Marked Point Processes method is adapt to 3D microfacies modeling of delta front reservoir with known sandbody geometry . The created microfacies model of the study atea is in line with dynamic production data.