【作者】 郑军；

【导师】 冯文光；

【作者基本信息】 成都理工大学 ， 油气田开发工程， 2011， 博士

【摘要】 大牛地气田是一个大型低渗致密多层叠合砂岩岩性气藏,该气田具有“一大、一多、一强、三低”的特点(储量规模大：大型气田；多套储层：7套含气层位,纵向上大面积叠加；储层非均质性强：以河流相沉积为主,储层厚度纵横向变化大；低压、低渗、低产：压力系数低0.89～0.98,储层渗透率小于1毫达西,单井产量低0.5-2万方/日),开采难度极大。气田于2005年建产,2008年底累计建成天然气产能23亿方／年,供气量占大华北地区总供气量的58.23%,随着榆济管线的建成,大牛地气田天然气稳定供应的重要性日益凸出。根据2005年气田开发方案的认识,老区气藏将很快进入递减期,每年将有近1亿方产能递减,因此,对大牛地老区气藏中后期的稳产技术研究亟待开展。本论文从基础做起,从气藏基本地质特征研究入手,利用气藏描述、动态分析、室内模拟实验和数值模拟技术相结合的手段实现对气藏的认识,具体为：通过储层流动单元划分和气藏精细建模,认识气藏的物性展布以及非均值特征；通过气藏单井生产特征、气井积液排液规律、气藏产量压力变化规律的分析,进行开发特征研究,掌握目前气藏开发状况及生产规律；通过单岩心以及并联组合长岩心模拟实验,弄清气藏采收率情况以及多层合采时机；通过气藏数值模拟研究,弄清气藏剩余气分布规律。在以上对气藏进行深入认识的基础上,综合开发地质、气藏动态特征、气藏生产实验模拟、储层建模研究以及气藏数值模拟研究,客观评价气藏在生产过程中产生的问题及开发潜力,提出了针对低渗致密多层叠合砂岩气藏不同开发阶段的三项稳产技术：井网完善技术、气藏合采技术和气藏增压技术；经预测三项稳产技术方案年增产1.86亿方以上,能再延长老区气藏3年左右的稳产期,将产生巨大的经济效益和社会效益。论文在确定该类气藏的临界携液流量、多层合采时机、考虑人工压裂缝分布的渗透率模型、考虑流动单元和应力敏感的气藏数值模拟方面具有创新性,并最终形成了一套适合于大牛地气田低渗致密气藏的稳产技术,为气田开发中后期提供技术保证。同时,还为我国其它地区低渗致密气藏开发提供技术指导和有益的经验。更多还原

【Abstract】 Daniudi gas field is a large lithological reservoir of sandstone, with sandwich structure, which is tight with low permeability. The gas field is characterized by abundant in reserve, seven gas-bearing beds, strong inhomogeneity of reservoir, and low pressure, low permeability, low production. The sedimentary facies of the gas reservoir is mainly fluvial facies. The thickness of reservoir varies on longitudinal and fraverse. The pressure coefficient is 0.89-0.98. The permeability of reservoir is less than 1 md. The well production rate is also low, about 0.5～2x 104m3/per day. So that, it’s difficult to exploit. The gas field has produced since 2005. Until late in 2008, its production capacity is up to 23 x 108 m3/per year sum as yield. The air demand of it accounts for 58.23%of whole north china. With the construction of Yuji pipeline, the importance of stable gas supply supporting of Daniudi gas field is obvious increasingly. According to the development plan in 2005, the maturing gas field will soon enter the period of depletion, and the decreasing rate of production capacity may be 1 x 108 m3/per year. Therefore, it’s urgent to study the stable producing strategy of the maturing areas of Daniudi gas field in the middle and late period.Begin with the basic geological characteristic of the gas field, the thesis have achieved the new recognition of this gas field, using description technique for gas field, dynamic analysis, simulation experiment in lab and numerical modeling. The main content of the thesis include four aspects as follow. Firstly, the distribution of physical property and the inhomogeneity characteristic was determined by dividing flow units of the reservoir and fine modeling of gas field. Secondly, we have studied the development feature. The present situation of development the gas field and the law of production was learned, by analysis of single-well production characteristic, the law of loading and unloading, and the evolution of production and service pressure of the gas field. Thirdly, the recovery efficiency and the timing of commingling production ascertained, through the simulating experiment of single drill core and long drill core combination in parallel. Finally, the regularities of distribution of the residual gas in the gas field were determined, using the numerical modeling. Base on understanding the law of the gas field and integrating the development geology, dynamic characteristics of gas, simulation of gas production, reservoir modeling and Numerical simulation of gas, we evaluated objectively the potentiality of it, and proposed multi-layer composite for low permeability tight sandstone gas reservoirs in various stages of development of the three stable production technology. These are bowl perfect network technology, gas technology and gas reservoir pressurization commingled stable technology. By predicting the three stable yields strategy can increase production more than 1.86×108m3 per year. This strategy will prolong about 3 years of stabilized production period, so that there will be a huge economic efficiency and social benefit.The thesis is innovative, for example determining the critical liquid carrying flow rate of the gas reservoir, the timing of commingling production, and numerical modeling of the gas reservoir in consideration of permeability distribution model of artificial pressure-break, flow units, and stress sensitivity. At last, the technology of stable yields is established, which is adapt for the low pressure and tight gas reservoir in Daniudi gas field. It supports technical assurance for the development of the gas field in the middle and late period. Meanwhile, it has provided technological guidance and useful lesson for the other tight gas reservoirs with low pressure and tight in our country.更多还原