致密气有效砂体结构模型的构建方法及其应用  

Building and application of structure model on effective sandbody in tight gas wells

作　　者：郭智[1] 冀光[1] 姬鹏程 庞强[3] 马妍 Guo Zhi;Ji Guang;Ji Pengcheng;Pang Qiang;Ma Yan(PetroChina Research Institute of Petroleum Exploration&Development,Beijing 100083,China;No.5 Gas Production Plant,PetroChina Changqing Oilfield Company,Ordos,Inner Mongolia 017300,China;No.3 Gas Production Plant,PetroChina Changqing Oilfield Company,Ordos,Inner Mongolia 017300,China;No.11 Oil Production Plant,PetroChina Changqing Oilfield Company,Xifeng,Gansu 745000,China)

机构地区：[1]中国石油勘探开发研究院 [2]中国石油长庆油田公司第五采气厂 [3]中国石油长庆油田公司第三采气厂 [4]中国石油长庆油田公司第十一采油厂

出　　处：《天然气勘探与开发》2022年第2期71-80,共10页Natural Gas Exploration and Development

基　　金：中国石油天然气股份有限公司“十四五”前瞻性基础性技术攻关项目《致密气勘探开发技术研究》下属课题“致密气主力开发区稳产技术研究”(编号:2021DJ2103);“致密气新区开发评价与开发技术研究”(编号:2021DJ2102)。

摘　　要：明确有效砂体规模及分布频率、搭建有效砂体结构模型,对于致密气井网优化调整及气田高效开发具有重要意义。以苏里格气田中区二叠系石盒子组8段、山西组1段、2段为研究对象,按照先搭建整体框架、再丰富层段细节的研究思路,提出了储层结构模型的4步构建方法和流程:①通过野外露头观测、沉积物理模拟等多手段拟合有效单砂体的长宽比和宽厚比等参数,测算有效单砂体平均规模;②充分利用开发中的海量数据,结合地质统计学、概率论等方法,对储层平面非均质性做一定的抽提和简化,判断多层叠合后每平方千米发育的有效单砂体个数;③基于不同砂组有效砂体发育频率、储量比例及单砂体厚度差异,明确各砂组有效单砂体规模及发育个数;④结合各小层有效砂体累计厚度及钻遇率,建立精确到开发小层的有效砂体结构模型。研究表明:①有效单砂体平均规模0.186 km^(2),平均储量0.0559×10^(8) m^(3);②在储量丰度约1.5×10^(8) m^(3)/km^(2)条件下,1 km^(2)发育25~30个有效单砂体;③在井距600 m、500 m、400 m、300 m下可分别控制38%、47%、57%、69%的有效砂体及53%、66%、76%、84%的储量;④随着井密度的增加,井网对有效砂体控制程度的增幅变大,对储量控制程度的增幅减小。Clarifying scale and distribution of effective sandbody and building a structure model on the sandbody are significant for optimization of tight gas well pattern and efficient development of gas reservoirs.So,the Permian Shihezi 8 Member and Shanxi 1 and Shanxi 2 member in central Sulige gasfield were taken as examples.And a four-step procedure to build this model has been proposed.First,fit such parameters as length-width ratio and width-thickness ratio of effective sandbody by way of outcrop observation and sedimentary and physical simulation,and estimate the average scale of effective sandbody.Second,extract and simplify the heterogeneity by using massive development data and geostatistics,probability theory,and other methods,and estimate the quantity of effective sandbody per square kilometer after multiple superposition.Third,determine the scale and quantity of effective sandbody in each sand group according to distribution,reserve proportion,and thickness difference of effective sandbody in each sand group.Fourth,establish the layer-based structural model on effective sandbody with consideration to the cumulative thickness and drilling rate of effective sandbody.Results show that the average scale of effective sandbody is 0.186 km^(2),and the average reserves are 0.0559×10^(8) m^(3).Given the reserve abundance of about 1.5×10^(8) m^(3)/km^(2),there are 25 to 30 effective sandbodies per one km^(2).With the well spacing of 600 m,500 m,400 m,and 300 m,38%,47%,57%,and 69%of effective sandbodies,and 53%,66%,76%and 84%of reserves can be controlled respectively.With the increase of well density,the well pattern demonstrates a higher increase in the extent of control on effective sandbody,but a smaller increase in the extent of control on reserves.

关 键 词：苏里格气田 二叠纪 透镜状 致密砂岩气 有效砂体 储层结构模型 井网优化 

分 类 号：P618.13[天文地球—矿床学]