沁水盆地煤层气地面工艺技术.pdf

作者简介王红霞,女,工程师;现从事天然气和煤层气工程设计工作。地址710021陕西省西安市未央区长庆大厦904 室。电话02986592634 ,13032962348。E2mail ctec2whx 99188. com 沁水盆地煤层气地面工艺技术 王红霞 刘 祎 王登海 陶 永 薛 岗 西安长庆科技工程公司 王红霞等.沁水盆地煤层气地面工艺技术.天然气工业,2008 ,283 1092110. 摘 要 沁水盆地煤层气资源丰富,其开发和利用具有重要意义。针对沁水盆地煤层气田低渗、 低压、 低产等 特点,介绍了适用于沁水盆地煤层气田地面建设的 “低压集气、 单井简易计量、 多井单管串接、 二次增压、 集中处理” 等一系列集输新工艺技术,以便为今后煤层气的工业化开发和建设提供有益的借鉴。 主题词 沁水盆地 煤层气 集输流程 工艺 优化设计 一、 煤层气资源开发特点 山西省沁水盆地是我国重要的煤层气勘探地 区,蕴藏着丰富的煤炭资源和煤层气资源。其煤层 气田具有低渗、 低压、 低产等特点,开发投入高、 产出 低、 风险大,具有以下特点[123] ① 单井产量低,井口压力低,气田单位产能建井 数多,地面建设投资控制难度增大;② 整个气田生产 处于低压生产状态,合理确定系统压力困难;③ 初期 单井产水较多,水型以NaHCO3型为主,随着开采时 间的延续,产水量逐步减少;④ 煤层气田单井产气压 力低,如果要满足外输要求,集输系统投资较高;⑤ 气 田采用区块接替的开发方式,造成地面集输系统部分 设施的废弃;⑥ 煤层气中饱和水蒸气含量较高。 二、 地面集输工艺的主要特点 目前,在沁水盆地进行煤层气开发的公司有中 国石油华北油田煤层气分公司、 中联煤公司和晋煤 集团等。虽然沁水盆地已建成小型煤层气开发试验 工程,但工程投资高,不能满足大规模外输的要求。 由于煤层气田具有单井产量低、 井口压力低等特点, 采用常规的天然气集输工艺也不能适应煤层气田的 合理开发,故需创建一套低成本高效率的煤层气开 发模式,摸索出一整套完善、 可行的地面集输工艺, 以满足国内煤层气低成本大规模开发的需要。 中国石油在做好开发试验的同时,开展了大量 地面集输工艺研究与实践工作。2006年中国石油在 沁水盆地煤层气田开始试采与地面建设工业试验, 并已取得良好的成果[4];2007年开始建设整个沁水 盆地煤层气田的中央处理厂和外输管道工程,标志着 我国煤层气工业化大规模开发的开始[5]。经过多年 来不断的探索与优化,沁水盆地煤层气田的开发形成 了一套独特的集输新工艺技术,其主要特点如下 1.总工艺流程 沁水盆地煤层气田具有井口压力和初期产量 低,单井产气量低,甲烷含量高,基本上不含重烃和 硫份以及生产周期长等特点。根据这些特点,借鉴 苏里格气田集输工艺的研究成果,并充分总结苏里 格气田试采、 开发和已建煤层气试验工程的经验,分 析各种低产低压气田的总体工艺流程,经过反复论 证、 简化优化,确定了 “井口 采气管网 集气站 中央处理厂 外输” 这一适合煤层气集输的总工艺 流程,采用 “低压集气、 单井简易计量、 多井单管串接、 二次增压、 集中处理” 等适合于煤层气开发的地面工 艺技术,大大简化了工艺流程,降低了工程投资。 2.低压集气工艺 第一步,采用管网瞬时模拟计算软件Pipeline Studios对采气管网的布局进行模拟计算,按井口压 力0. 2～0. 5 MPa、 进站压力大于等于0. 05～0. 15 MPa、 单井产量0. 18～0. 28104m3/ d建立计算 模型,对采气管线长度和管线压降进行优化。 第二步,采用HYSYS软件模拟计算井口形成 水合物的温度,并以采集气输送过程中水合物形成 温度低于环境温度时的压力作为设计压力。确定井 口压力在0. 2～0. 5 MPa下,采气管线埋设于最大冻 901 第28卷第3期 天 然 气 工 业 储运与集输工程 土层以下防止形成水合物的低压采集气工艺。 3.单井简易计量工艺 井口智能计量投资大、 维护工作量高,虽可降低 煤层气田工程投资,但不适合煤层气田的大规模开 发,通过对比试采工程中智能和简易流量计的使用, 提出采用简易旋进流量计的方案。 首先对流量计进行现场选型试验,将满足计量 精度、 能够适合现场流量计量和操作需要作为选型 的依据,然后在单井前把几种流量计按照计量精度 的高低依次串接,从准确度、 操作、 费用等因素综合 确定流量计的选型。 由于旋进流量计现场试验情况较好,且精度能 满足煤层气气田的单井计量需要,价格便宜,故推荐 使用简易旋进流量计作为单井煤层气计量仪表。 4.多井单管串接工艺 通过对国内外单井间串接的经验借鉴以及工艺 模拟,以最小路径为原则,进行采气管网的串接,形 成多井单管的管网形式。通过采气管线把相邻的几 口气井串接到采气干管,汇合后集中进站。简化了 采气管网系统的建设,降低了投资和运行费用。 5.集气站分散增压、 中央处理厂二次增压工艺 煤层气的开发应上、 中、 下游统一考虑,协调发 展,系统中各点压力从井口的0. 2～0. 5 MPa至外 输所要求的6 MPa的确定是经济合理开发煤层气 田的技术基础。为此,采用集气站分散增压,以降低 管网投资,满足煤层气输送要求;并在中央处理厂设 置增压装置,以满足外输压力要求。通过二次增压, 使煤层气压力逐级增高,达到外输压力要求后输入 西气东输管道。 经优化设计和技术经济比较,集气站出站压力 为1. 4～2. 0 MPa ;中央处理进厂压力1. 0 MPa ,出 厂压力为5. 7 MPa。具体工艺流程如下 1湿气通过采气干管进入集气站的压力为 0. 05～0. 15 MPa ,在集气站的进站总管汇合后,经 常温分离、 增压增压到1. 6～2. 0 MPa、 计量后去 中央处理厂集中处理。 2在中央处理厂,煤层气经过滤分离、 计量、 增 压、 脱水、 贸易计量后去外输管道,处理合格后的干 气输至西气东输管道的沁水压气站,进入西气东输 管道。 6.先增压后脱水的集中处理工艺 中央处理厂的主要工艺过程为增压和脱水。在 脱水装置前进行增压还是在脱水装置后进行增压对 中央处理厂工艺参数选取、 运行费用及投资影响较 大,必须进行对比分析和优选。不同压力下脱水后 的含水量都应满足外输压力下的水露点要求。先脱 水后增压工艺的脱水装置一次投资高,脱水再生负 荷大,运行费用高;设备体积大,占地面积大,工艺管 线管径大。而先增压后脱水工艺的一次投资低,脱 水再生负荷较小;脱水装置的操作压力较高,设备体 积小,占地面积小,工艺管线管径小。故在节约投 资,降低能耗的原则下,采用先增压后脱水三甘醇 脱水的工艺。 三、 结 论 通过不断优化与创新,沁水盆地煤层气田的开 发形成了国内煤层气田开发新的模式,总结出了 “低 压集气、 单井简易计量、 多井单管串接、 二次增压、 集 中处理” 等适合于煤层气开发的地面集输工艺技术。 整套地面集输工艺技术简单适用、 安全可靠,适应性 强,使平均单井地面建设投资比预期的投资大大降 低,为有效开发煤层气田提供了一种经济可靠适用 的工艺模式,为煤层气工业化开发奠定了良好的基 础,对我国今后开发煤层气资源具有重大意义。 参 考 文 献 [1]孙茂远,范志强.中国煤层气开发利用现状及产业化战略 选择[J ].天然气工业,2007 ,273 125. [2]中国石油学会石油地质专业委员会,中国煤炭学会煤层 气专业委员会.煤层气勘探开发理论与实践[ M].北京 石油工业出版社,2007. [3]石书灿,林晓英,李玉魁.沁水盆地南部煤层气藏特征 [J ].西南石油大学学报,2007 ,292 54256. [4]中国勘探开发研究院廊坊分院,西安长庆科技工程有限 责任公司,华北油田公司采油院,等.沁水煤层气田樊庄 区块5亿立方米产能建设开发方案[ R]. [出版地不详] [出版者不详] ,2006. [5]西安长庆科技工程有限责任公司.山西沁水盆地煤层气 中央处理厂可行性研究报告[ R].西安[出版者不详] , 2007. 修改回稿日期 2008201203 编辑 罗冬梅 011 储运与集输工程 天 然 气 工 业 2008年3月 test in Daqing Wuzhan low2permeability gas reservoir indicates that both porosity and permeability are sensitive to pressure. Thus , on the basis of change law that core porosity and permeability in Daqing Wuzhan gas reservoir are varied with net confi2 ning pressure , a numerical simulation model considering media deation caused by porosity and permeability has been estab2 lished and is solved by using the IMDES . Through the analysis on history matching with yields by 5 gas wells in Daqing Wuzhan gas reservoir , it is found that the history matching is consistent with mining field when considering the sensitivity of permeability and porosity to pressure comprehensively , and proved that the simulation can be applied in analogous res2 ervoirs. Meanwhile , simulation of gas reservoir has also showed that the well control dynamic reserves of gas reservoir are rela2 tively low and new development wells should be deployed in areas with great potential and with highly2increased thickness of reservoirs so as to improve the development efficiency of gas reservoirs. SUBJECT HEADINGS Daqing Oilfield , low2permeability reservoir , geological deation , numerical simulation , stress , study YANG Er2long, born in 1976 , is studying for a Ph. D degree and has been mainly engaged in research works on oil field devel2 opment engineering. AddMOE Key Laboratory for Enhanced Oil and Gas Recovery , Daqing Petroleum Institute , No. 199 , Fazhan Rd. , Gaoxin District , Daqing City , Heilongjiang Province 163318 ,P. R. China Tel 86245926506 789 Mobile 86213199071896 E2mail yengine 126. com 16 www. trqgy. cn/ e/abstracts.asp CBM MEASUREMENT BY DIFFERENTIAL PRESSURE CONE METER Philip A. Lawrence1, SUN Yan2zuo21Cameron Measurement Systems ; 2 Ination Science and Techni2 cal College of Beijing University of Technology .N A TUR. GA S IN D.VOLUME 28 , ISSUE 3 , pp. 1052 108 , 3/ 25/ 2008. ISSN 100020976 ; In Chinese ABSTRACT There is huge CBM resource in the U. S. A. , and it is estimated that 30 thousand CBM wells will be drilled only in the Rocky Mountainous area in the future 8 or 10 years. However , some of the challenges that CBM producers experience relate to accurate measurement at the wellhead whilst maintaining a low differential pressure across a system and also dealing with wet gas issues in the meter run. This paper introduced the use of differential pressure meters which use a double cone as the primary differential pressure producer. Its typical structure helps the V2cone flow meter have strong ability of flow adjust2 ment , and operate with good accuracy at low DP ’s. Its unique design on the V2shape column is not only beneficial to the extrac2 tion of CBM , but also can prevent CBM wells from cross interference or from CBM gas injecting into the neighbouring wells due to malfunction of a certain valve.The V2cone flow meters have been widely used in the exploitation of CBM in the U. S. A. SUBJECT HEADINGS U. S. A , CBM , flow gaging ,v2cone flow meter , tubing system , flow adjustment Philip A. Lawrence is manager at Cameron Measurement Systems. Add14450 J FK BLVD , HOUSTON , TX 77032 , USA. Mobile12819243258. E2mail phil2lawrence c2a2m. com SUNYan2zuo professor is also one member of the 6th NGI Editorial Committee. AddRoom 409 , North Unit , Block 1 , Shenggunanli , Chaoyang District , Beijing 100029 ,P. R. China Tel 8621026443 4677 E2mail yzsun36 sina. com CBM GROUND TECHNOLOGY IN QINSHUI BASIN WANG Hong2xia , LIU Yi , WANGDeng2hai , TAO Yong , XUE Gang Science and Technology Engineer2 ing Company of PetroChina Changqing Oilfield Company .N A TUR.GA S IN D.VOLUME 28 , ISSUE 3 , pp. 1092110 , 3/ 25/ 2008. ISSN 100020976 ; In Chinese ABSTRACT The Qinshui Basin is rich in coalbed methane whose development and usage are of importance. In view of the characteristics of coalbed methane in the Qinshui Basin such as low permeability , low pressure and low production , this article introduces briefly a set of new gathering technology that is suitable for the ground construction of coal bed methane in the Qin2 shui Basin , for example , gas collection with low pressure , simple calculation of single well , multiwell pipe string connection , N A TURAL GA S IN DUS TR Y, VOLUME 28 ,ISSUE 3 ,2008 MARCH25 ,2008 secondary boosting and central treatment , which can provide beneficial reference for industrial construction and development of coalbed methane. SUBJECT HEADINGS Qinshui Basin , coalbed methane , gathering process , technique , optimistic design WANG Hong2xia engineer , has been engaged in design on natural gas engineering and coalbed methane engineering. AddScience and Technology Engineering Company of PetroChina Changqing Oilfield Company , Room 904 , Changqing Build2 ing , Weiyang District , Xi ’an , Shaanxi Province 710016 ,P. R. China Tel 8622928659 2634 Mobile 86213032962348 E2mail ctec2whx 99188. com AMERICAN TECHNOLOGY ON CBM GAS GATHERING AND GROUND TRANSPORTATION XIAO Yan , MENG Qing2hua , LUO Gang2qiang , YUAN Xian2yong , YAO Lin2yu Ground Engineering Department of Technology Research Institute , SINOPEC Southwest Branch Company .N A TUR.GA S IN D.VOLUME 28 , ISSUE 3 , pp. 1112113 , 3/ 25/ 2008. ISSN 100020976 ; In Chinese ABSTRACT While the global natural gas resource is depleting day by day , the energy demand is soaring and global environ2 ment protection has to be more seriously handled. CBM as a great potential alternative energy plays an important role in the en2 ergy mix. The United States of America has kept ahead in the world her research studies , exploration , development and utiliza2 tion of CBM. Taking the San Juan Basin and the Black Warrior Basin as examples , this paper introduced the progression of CBM from coal seam to commercial pipeline which was a complex process involving extraction , gathering , processing , and transportation. Hopefully good experiences from America would provide helpful references for Chinese CBM development. SUBJECT HEADINGS CBM , well site , gathering system , central disposal station , water disposal , corrosion XIAO Yan, born in 1982 , graduated in oil and gas storage and transmission from Southwest Petroleum University in 2007. She is now an assistant engineer at Ground Engineering Department of Technology Research Institute , SINOPEC Southwest Branch Company , being engaged in research on gas network programming and ground gas gathering technology. AddGround Engineering Department of Technology Research Institute , No. 298 , North Longquanshan Rd. , Jingyan District , Deyang City , Sichuan Province 610800 ,P. R. China Tel 86283822552 875 Mobile 86213408143525 E2mail xywhat 163. com www. trqgy. cn/ e/abstracts.asp 17 STUDY AND DEVELOPMENT ON SIMULATION SOFTWARE FOR “SICHUAN2TO2EAST GAS TRANS2 MISSION“ PIPELINE TANGJian2feng1, LI Yu2xing1, ZHANGJian2, LIU Jian2wu2, DU Pei2en21China University of Petrole2 umEast China ; 2 Engineering In Chinese ABSTRACT With the initiation of such important national natural gas pipeline project as Sichuan2to2East gas transmission , to develop pipeline simulation software with independent intellectual property is on the trend. On the background of “Sichuan2to2 East Gas Transmission Project“ , this paper adopts continuity equation , momentum equation , energy equation and SHBWR e2 quation to develop static and dynamic mathematical model to simulate the gas flow in pipelines more actually , which are numeri2 cally solved respectively by four2order Runge2Kutta and implicit center finite difference . In addition , many op2 erational modes and models on static and/or dynamic calculation of peak shaving capacity and dynamic forecasting are analyzed. Based on data base and graphic programming , the Sichuan2to2East Gas Transmission Simulation Software is developed by C Builder 6. 0 in which the advantage of both industrial control software and calculation software are included effectively. The core program as well as its calculation results has been verified with software TGNET and some designing materials. It has been proved by practice that the software is credible with good values for project application. SUBJECT HEADINGS Sichuan2to2East Gas Transmission , natural gas pipeline , software , simulation , mathematical model TANGJian2feng associate professor , born in 1973 , graduated in heat and gas supply major and air and air2conditioner major from the Harbin University of Civil Engineering and Architecture. He is now being engaged in natural gas transportation , gas hydrate gathering and gas2fluid mixed gathering optimization. AddStorage and Transportation Engineering Department , Storage and Construction Institute , China University of Petroleum , N A TURAL GA S IN DUS TR Y, VOLUME 28 ,ISSUE 3 ,2008 MARCH25 ,2008