低效煤层气井多次压裂增效开发技术研究

延川南煤层气田经过6年多开发实践,认识到储层改造体积小导致的缝控储量规模不足是煤层气井低产主因之一。气田呈现出低效井井数占比高、贡献产量小的生产特征。为改善气田开发形势,急需开展低效井增效开发技术攻关。理论研究表明,水平应力差异系数(K)越小,水力压裂越易形成复杂缝网;压裂施工产生的诱导应力能够改变储层应力状态,降低K值;多次压裂施工能够多次诱导储层主应力重定向,有助于低渗煤层形成复杂缝网系统。以鄂尔多斯盆地东南缘延川南煤层气田稳产期短、剩余储量丰富的低产气井为研究对象,开展以梯次提高排量、逐渐增大前置液量、组合加入支撑剂为主要特征的多次压裂增效开发技术现场试验。应用后,监测的裂缝缝长是单次施工产生的缝长3倍以上,裂缝形态由单一裂缝转向复杂缝网,有效扩大储层改造体积;通过多次组合加砂实现缝网有效支撑,在深部煤储层建立高效导流通道。复产后,试验井气液平均日产出量分别提高5倍、7倍,评估最终可采储量增加5倍左右,提高煤层气单井产量和最终采收率,实现低效煤层气井高效治理,增产效果显著。在随后推广应用的22口煤层气井中,实现单日平均产量和最终累计产量的双突破,证实多次压裂增效开发技术能够提高深...     

焦作煤田煤层气赋存地质特征与有利区块分析

根据煤田地质勘查和煤层气参数井资料,对焦作煤田煤层气赋存的地质条件和煤层气储层特征进行分析,认为煤田内主要储层为山西组二1煤,煤层的含气量与煤层厚度、煤层的上覆有效地层厚度、煤层割理的发育程度、顶、底板围岩的性质有关,受断裂构造的控制将煤田分成了南、中、北三个构造断块、其中南部和中部断块气含量高,应用层次分析法经计算得到该煤田的综合评价,且优选出恩村井田、古汉山-位村井田、九里山为有利区块,其成藏条件优越,通过试井得出破裂压力与闭合压力差值小,且不利于通过压裂产生有效延伸长度和导流能力的裂缝,故应采用多级脉冲加载压裂技术,以保证压裂改造效果,达到改善储层导流能力的目的。     

沁水煤层气田郑庄区块二次压裂增产技术研究

郑庄区块投入开发后存在部分低产井,主因是首次压裂工艺技术不适应低渗透、复杂高阶煤储层特性所致,为了提高该区块开发效果,研究了与该区块煤储层特性相适应的二次压裂增产技术。通过开展煤储层特性判别、二次压裂增产机理研究、改变压裂施工思路等工作,建立了适应不同煤储层特性的4种增产技术,并进行了80口井的现场应用。应用结果表明:低渗透煤层、构造软煤、大裂隙煤层实施二次压裂增产技术后,形成了新的人工裂缝或人工缝网,煤储层渗透率得到改善,能够提高低产井产气量,单井平均日增气650 m~3/d以上,该技术解决了郑庄区块低产井问题,对同类型煤层气田提高开发效果提供了参考。     

煤层气藏水平井分段压裂裂缝参数优化

研究区块煤层气藏储层渗透率极低,使用水平井分段压裂技术有利于煤层气的开发。针对不同裂缝参数对水平井产能的影响,进行数值模拟研究,并优选出最佳的裂缝组合形式。首先,结合研究区块的地质特征,采用双孔模型进一步证明了压裂的必要性,并在此基础上,优选出最佳的裂缝参数组合形式为:1 500 m水平段上压裂15段,共45条主裂缝,裂缝间距为33 m,裂缝半长为350 m,导流能力为100 mD·m。该研究思路及方法对煤层气藏水平井的分段压裂具有指导意义。     

高能气体压裂技术在云南恩洪盆地煤层气开发中的试验应用

恩洪盆地煤层气资源丰富,但煤储层渗透率低、水敏性强,开发难度大。采用水力加砂压裂技术对煤层气井进行增产改造效果不理想,因此提出并开展了高能气体压裂技术在煤层气开发中的试验应用,以期在煤储层中产生和形成多裂缝体系,同时产生较强的脉冲震荡作用于地层,改善和提高煤层导流能力。本文介绍了高能气体压裂技术在B井煤储层改造上的试验应用,分析了作用机理、工艺设计等,并提出了今后的研究方向,对探索我国煤层气有效开发的新途径具有重要的意义。     

延川南区块煤层气排采工艺技术现状及建议

延川南区块煤层气部分排采井因煤粉从煤层中析出至井筒造成螺杆泵频繁卡泵,检泵周期短,无法实现煤层气的连续性排采。文中介绍了延川南区块煤层气排采井举升工艺技术现状,找出螺杆泵排采工艺中存在的主要问题,提出相应的技术对策,对提高延川南区块煤层气整体开发水平具有一定的指导意义。     

煤层气井同步压裂工艺现场实践

针对沁南东区块煤储层特点,通过对煤层气"吸附-解吸"原理的研究,结合排水降压的控制方法,在试验区块压裂效果比对优选基础上,进行了2个井组的煤层气井同步压裂技术先导试验并获得成功,实施效果的跟踪评价表明,采用该项技术,排采效果明显,比同一区块其他煤层气井气量有较大提高。     

不同类型压裂返排液对煤层气储层的伤害实验研究

为了明确压裂返排液对煤层气储层的伤害情况,选择山西沁水盆地某煤层气矿区储层煤样和不同类型现场压裂返排液为研究对象,通过煤岩心驱替实验、煤储层裂缝导流能力实验以及煤层气解吸实验评价了不同类型压裂返排液对煤层气储层的伤害情况。结果表明:经过不同类型的压裂返排液污染后,目标区块煤层气储层煤岩心渗透率、裂缝导流能力和煤层气解吸能力均有不同程度的下降现象,其中线性胶压裂返排液对煤层气储层的伤害程度最大,清洁压裂返排液次之,活性水压裂返排液的伤害程度最小;结合不同类型压裂返排液的基本性能评价情况,认为压裂返排液对煤层气储层的伤害原因主要包括固相颗粒堵塞损害、微粒运移堵塞损害和水锁损害等。     

解堵性二次压裂在樊庄煤层气井的应用

樊庄区块煤层气并使用清洁液压裂后,由于破胶不彻底导致裂缝堵塞而使煤层气井产量低。通过对压裂液进行室内实验优选出适合樊庄区块煤层气井的压裂液体系,优化施工工艺,开展活性水二次压裂,达到解堵增产的目的。樊庄区块现场实施2l井次,取得了很好的增产效果。     

煤层气井水力压裂裂缝导流能力实验评价

本文主要围绕煤层气井压裂裂缝导流能力实验评价展开介绍。煤层气井水压裂裂缝导流能力实验表明，与砂岩地层不同，煤层的硬度较小，压裂中支撑剂嵌入情况较严重，导致导流能力降低，加大铺砂浓度能在很大程度上提高煤层裂缝的导流能力。实验中，煤层闭合压力是一个重要的参数，实验对比了在不同闭合压力下，支撑剂颗粒的破碎与嵌入、铺砂浓度、石英砂支撑剂粒径的选择等因素对煤层导流能力的影响。本文所得出的结论对今后煤层气的研究工作及现场施工具有一定的指导意义。     

Current situation and future trend of China rare earth luminescent material industry

<正>Rare earth luminescent material is one of the most important application sectors of rare earths.China enjoys the exceptional advantage to develop rare earth luminescent material for its abundant rare earth resources.After several decades'endeavor,China's rare earth luminescent material industry,headed by rare earth phosphor for lamp and LED and high efficient rare earth energy-saving light source,has been gradually developed into a scale industry.China has become a major production base of rare earth phosphor for lamps and rare earth     

China rare earth market review

正June 1~10,2014Rare earth market remained weak.Quoted price of rare earth products was similar to that in May.There was no sign of recovery in downstream market.The market of NdFeB magnetic materials and phosphor was depressed.Catalyst,polishing powder and ceramic industries remained inactive.Demand from downstream industry was soft.Consumers purchased on their needs.Suppliers had strong intention to sell.Prices of rare earth products     

Annual Report analysis of Chinese rare earth-related listed companies in 2013

<正>Chinese rare earth-related listed companies have published their 2013 annual reports.It can be understood from their reports that production and operation activities of Chinese rare earth-related companies were still heavily affected by macro economy and industrial policies.They basically followed the steps of national economy.In 2013,world economy recovered slowly but the economy     

Market opportunities and challenges for rare earth polishing powder

正1.Status of rare earth polishing powder Rare earth polishing powder with high content of cerium oxide began to replace iron oxide for glass polishing and became one of the key materials in glass polishing process since 1940.Compared with traditional iron oxide,rare earth polishing powder has many advantages,such as fast polishing rate,high polishing quality and long service life.It can achieve good surface quality and improve operation conditions.For example,in lens polishing,the polishing work that cerium     

Baotou Research Institute of Rare Earths developed a new RE alloy preparation technology

正Pyrometallurgy Laboratory of Baotou Research Institute of Rare Earths had independently developed a new preparation technology of rare earth alloy for NdFeB.The alloy can remarkably enhance the coercivity of NdFeB magnet but also evidently reduce the production cost of the magnet.The new master alloy was prepared in the kA pilot-scale electrolytic cell by the independent technology.The rare earth master alloy can be used as the raw material for NdFeB.Compared     

Market and recycling of NiMH battery

<正>Market status and future trend of NiMH battery1.Global market of small NiMH battery Global market size of small NiMH batteries declined year on year since 2011.The trend will continue to 2018,at the rate of 5%to 10%annually.Demand for small NiMH batteries will be stable gradually.Many electrical apparatuses are powered by the built-in lithium battery today,which is the main reason for the shrunk market of small NiMH batteries.But,for some products,small NiMH     

China rare earth market review

正September 1-10,2014 Affected by the National Day holiday,rare earth transaction was stagnant and the market showed a weak steady state.As there was no good news for downstream market,some products with flat demand would likely rally slightly for some time to     

2014 second batch of rare earth quota released

正~~     

矿用防爆轴流对旋主要通风机叶片ANSYS模态分析及应用

高效节能矿用防爆对旋主要通风机的叶片是主要通风机运行的关键部件,叶片在运行时不断受到气流的作用力,从而使叶片产生振动,当叶片振动的频率与叶片的固有频率接近时,容易产生共振从而导致叶片的断裂。一旦叶片断裂时,对主要通风机的安全运行产生致命的影响,从而导致矿山、化工等企业发生重大事故,将会产生不可估量的损失。基于有限元分析软件ANSYS,对高效节能矿用防爆轴流对旋主要通风机叶片进行模态分析及产生对应的六阶模态频率,对主要通风机叶片的运行频率、固有频率及产生的共振问题进行了原理分析,并且解决了叶片频率共振的问题,从而为主要通风机叶片结构设计提供理论依据,并对主要通风机叶片的安全运行提供保障。     

2013 NdFeB export analysis

<正>China totally exported nearly 24,000 tonsof NdFeB products during 201 3,including 18,825 tons of permanent magnet,valued USD 1.34 billion at an average price of 71.4 USD/kg;3,277 tons of NdFeB magnetic powder,valued USD 1 01 million at an average price of 30.9 USD/kg;1,334 tons of strip casting ribbon,with total export value of USD 74million at an average price of 55.3 USD/kg;and 586