鄂尔多斯盆地低渗透—致密气藏储量规模虽大,但储层物性差、非均质性强、储量动用程度低且差异大,要实现气藏的长期稳产及效益开发难度大.为此,以该盆地5个主力气田为研究对象,以效益开发为导向,以内部收益率为核心评价指标,结合动、静态特征对低渗透—致密气藏进行储量评价单元划分、储量分类评价和储量接替序列的建立,并针对不同类型的储量提出相适应的开发技术对策.研究结果表明:①该盆地单井动态储量小、产气量低,产气类型可以划分为多层协同供气和单层主力供气两种;②基于地质条件和单井动态特征相近的原则,结合开发管理区块分布情况,将该盆地内5个主力气田划分为11个储量评价单元,以内部收益率30％、8％和5％作为界限,把储量评价单元划分为高效、效益、低效和难动用4种储量类型;③以内部收益率8％为有效开发的基准,将其对应的井均估算最终开采量(EUR)与各个储量评价单元实际的井均EUR对比,按照效益由高到底的顺序,建立了储量评价单元经济有效动用序列;④高效储量适宜采取增压开采和局部井网调整对策,效益储量需通过井网加密提高储量动用程度,低效储量应采取富集区优选、滚动开发对策,难动用储量需加大技术攻关以实现效益开发.结论 认为,该研究成果有助于提高鄂尔多斯盆地天然气储量的动用程度,可以为该盆地天然气长远开发战略的制订提供技术支撑.

天然气从生产到外输采用管道输送,管道沿途环境地形复杂、部分区域人烟密集,存在很多安全隐患.发生管道破损等情况时,管道阀室的开关执行状态关系到整个事故的有效控制.为此,提高天然气集输系统联动联锁安全控制水平,可有效提高突发事件的应急安全管控能力.文章在井、站、管道运行控制运行现状基础上,分析对管道沿途阀门、管道上下游集输站点以及管道所涉及的生产区域进行联动联锁控制必要性,并结合分散在集输过程各个区域控制器的特性,进行系统集中优化,完善控制原理,达到了联动联锁安全应急控制目标,并在实践中得到有效应用,提高了天然气安全集输水平.

Based on the analysis of influencing factors of tight gas recovery and reservoir geological characteristics, the types of remaining tight gas reserves in the Sulige gas field are summarized from the perspective of residual gas genesis to estimate residual gas reserves of different types and provide corresponding technical strategies for enhancing gas recovery. The residual gas reserves in the Sulige gas field can be divided into four types: well pattern uncontrollable, horizontal well missing, imperfect perforation, blocking zone in composite sandbodies. Among them, the uncontrolled remaining gas of well pattern and blocking zone in composite sandbodies are the main body for tapping potential and improving recovery factor, and well pattern infilling adjustment is the main means. Taking into account reservoir geological characteristics, production dynamic response and economic benefit requirements, four methods for infilling vertical well pattern, i.e., quantitative geological model method, dynamic controlled range of gas well method, production interference method and economic and technical index evaluation method, as well as a design method of combined vertical well pattern with horizontal well pattern are established. Under certain economic and technological conditions, the reasonable well pattern density of enrichment zone of gas field is proved to be 4 wells per square kilometers, which can increase the recovery rate of the gas field from 32% to about50%. Meanwhile, five matching techniques for enhancing gas recovery aimed at interlayer undeveloped residual gas have been formed,including tapping potential of old wells, technological technology optimizing of new wells, rational production system optimizing, drainage and gas producing, and reducing waste production, which could increase the recovery rate for 5% based on well pattern infilling. The research results provide effective support for the long-term stable production of 230×10~8 m~3/a of the Sulige gas field and production growth in the Changqing gas area.

苏里格气田是中国致密砂岩气的典型代表,储层低渗致密,具有强非均质性,区块间差异显著,采用主体开发井网较难实现区块储量的整体有效动用,由于采收率低,故针对不同分类储量区分别进行加密调整.该研究优选气田中部苏x区块为研究区,通过分析该区块砂体分布特征等因素分析,以储量分类指数为主要依据,将研究区储量分为5类,在同时考虑技术和经济条件的前提下,对该区块进行井网加密设计.

The Chang 8 interval of the Upper Triassic Yanchang Formation is a typical low-porosity and low-permeability reservoir in Jiyuan area of the Ordos Basin.Researches of the main controlling factors,the formation conditions of high quality reservoirs and forecast of the favorable target have great significance for the exploration of potential oil and gas resources.Comprehensive analyses have been made on the sedimentary characteristics,property characteristics,rock thin sections,casting thin sections and so on.This paper discusses the distribution of favorable reservoir,the petrology characteristics,the pore texture and pore types,the physical property and the diagenesis types,which finally makes a comprehensive prediction of the distribution characteristics of favorable reservoir area.The results reflect that the lithic arkose is developed well and the cement,especially the ferrocalcite,is general in the Chang 8 interval of the study area.It is poor of the physical properties of the whole reservoir which is characterized by strong heterogeneity.The pore types mainly include residual intergranular pore and dissolution pore.The reservoir is controlled by the sedimentation,diagenisis and tectonism.Based on the above analyses,we forecasted the favorable reservoir in the Jiyuan area.