第37卷第3期 2016年6月
文章编号：1001-3873(2016)03-0360-05
新疆石油地质
XINJIANG PETROLEUM GEOLOGY DOI:10.7657/XJPG20160323
Vol. 37,No.3 Jun.2016
一种计算致密砂岩油气藏有效孔喉下限的新方法
以苏重格气由盒8气藏为例刘晓鹏，刘新社，赵会涛，王怀厂，张辉
（中国石油长庆油田分公司a.勘探开发研究院；b.低渗透油气田勘探开发国家工程实验室，西安710018）
摘要：鉴于压乘实验过程与油气充注成藏过程相类似，认为在密闭取心样品毛细管压力曲线上，与密闭取心样品含油气饱和度相等的进汞饱和度毛细管压力相对应的喉道半径为油气蔗有效临界孔喉率径，具有代表性的密闭取心样品中最小的有效临界孔唤直径为油气藏有效孔唤下限。提出了一种准确、快捷计算致密砂岩油气蔗有效孔喉下限的新方法，分析讨论了目前求取有效孔唤下限主要方法的优势及其局限性。以苏里格气田盒8气藏为例，采用密闭取心样品毛细管压力曲线法，求取的盒8气截有效孔唤半径下限约为53.3nm，由大于此喉道半径连通的孔隙体系才是勘探开发的主要对象。
关键词：苏里格气田；盒8气藏；致密砂岩油气藏；最小孔喉半径；水膜厚度；毛细管压力曲线
中图分类号：TE112.23
文献标识码：A
ANewMethod toCalculatetheLowerLimitof EffectivePoreThroatThresholdof Tight
Sandstone Reservoirs: A Case Study of He-8 Gas Reservoir in Sulige Gas Field
LIU Xiaopeng, LIU Xinshe,ZHAO Huitao,WANG Huaichang,ZHANGHui
(PetroChina Changqing Oilfield Company, a.Research Institute of Exploration and Development, b.National Engineering Laboration for Low
Permeability Petroleum Exploration and Development,Xi'an,Shaanxi 710018, China)
Abstract: Because the mercury injection process is similar to that of hydrocarbon charging and accumulation, it is considered that the throat radius corresponding to the capillary pressure of mercury injection saturation which equals to hydrocarbon saturation of sealed-cor-ing samples should be the effective pore throat radius threshold on the capillary pressure curves of sealed-coring samples, and the mini-mum effective pore throat diameter threshold in representative sealed-coring samples is the lower limit of effective pore throat of the reser-voir. The paper proposes a new method to calculate the lower limit of the effective pore throat threhold of tight sandstone reservoirs accu-rately and rapidly. It also discusses and analyzes the advantages and limitations of the current methods. Taking He-8 reservoir of Sulige gas field as an example and based on the method of capillary pressure curve of sealed-coring samples, the obtained effective pore throat thre hold of He-8 reservoir is 53.3 nm. Therefore, it is concluded that the pore systems connected by the pore throat with the radius more than 53.3 nm will be the main targets for exploration and development.
Keywords: Sulige gas field; He-8 gas reservoir; tight sandstone reservoir; mininum pore throat radius; water film thickness; capillary
pressurecurve
油气藏有效孔喉下限指油气藏储集层含油气的最小孔喉半径，其主要受储集层微观孔隙结构和油气充注条件的双重控制。有效孔喉下限是油气资源潜力、产能评价的重要参数，也是影响勘探开发决策的关键参数。随着致密砂岩储集层微观孔隙结构表征技术的不断发展，纳米级孔喉对油气存储和开发产量的贡献日益受到人们的关注"-6。笔者提出了一种利用密闭取心样品毛细管压力曲线求取致密砂岩油气藏有效孔喉下限的新方法，以苏里格气田盒8气藏为例，计算了致密砂岩油气藏有效孔喉下限。为确定勘探开发主体目标、舍弃对油气储集和产量没有贡献的
收稿日期：2015-10-19
修订日期：201601-11
致密砂岩、节约勘探开发成本提供了依据。研究现状
前人通过深人研究，归纳出3种计算油气藏有效孔喉下限的方法，分别为两倍水膜厚度+油气分子集合体粒径法、油气充注动力学模型法和环境扫描电镜
实测临界含油气孔喉法。 1.
两倍水膜厚度+油气分子集合体粒径法
此方法依据两倍水膜厚度与油气运移的分子集合体粒径之和来确定油气藏有效孔喉下限"。由于石油天然气中甲烷、乙烷、正戊烃和沥青分子直径分别
基金项目：国家科技重大专项（2011ZX05044；2011ZX05007-004）
作者简介：刘晓鹏（1978），男，陕西西安人，T.程师，油气地质，（Tel)15202908168（Email)liuxiaopl_cq@petrochina.com.cen 万方数据