我国气藏水平井技术应用综述_孙玉平

摘
要
随着我国天然气勘探开发的不断深入，复杂难开采的低品味储量比重不断上升，经济有效开发难度
逐步加大。

水平井技术是降低单位产能建设投资、提高开发效益的最有效手段之一，为此统计并分析了水平井在我国5种主要类型气藏开发应用中的经验教训，指出：水平井是经济开发低渗透砂岩气藏的有效方法，地质条件适应性是成功开发的关键；火山岩气藏Ⅰ类储层中的水平井开发是成功的，Ⅱ、Ⅲ类储层表现出一定的不适应性；疏松砂岩气藏水平井开发效果呈现出Ⅰ类好于Ⅱ类、Ⅱ类好于Ⅲ类的特征；准确钻遇有效储集层是水平井开发碳酸盐岩气藏的关键；水平井开发凝析气藏效果较好。

同时结合水平井技术的特点和实践经验，总结了该技术在气藏开发中的使用条件，并建议今后应持续开展水平井储层适应性、配套技术研发及经济效益分析工作。

关键词
水平井天然气藏适应性发展建议
综述
我国气藏水平井技术应用综述∗
孙玉平1
陆家亮1
巩玉政2
霍瑶1
杨广良3
（1.中国石油勘探开发研究院廊坊分院，河北廊坊065007；2.中国石油塔里木油田公司开发事业部桑吉作业区，新疆
库尔勒841000；
3.中国石油大学胜利学院石油工程系，山东
东营257097）
收稿日期：2010－10－22修订日期：2011－01－24
∗基金项目：中国石油科技部2008B-1101《特殊天然气藏开发技术应用基础研究》。

作者简介：孙玉平（1983－），硕士，从事天然气开发战略规划方案及基本方法研究。

E-mail:sunyuping01@ 网络出版时间：2011-02-17网址：/kcms/detail/51.1736.TE.20110217.1420.003.html
中图分类号：TE243.2
文献标识码：B
文章编号：2095-1132（2011）01-0024-04
Vol.5，No.1
Feb.2011
doi ：10.3969／j.issn.2095－1132.2011.01.006
2011年第5卷·第1期
0引言
国外水平井技术于1928年提出[1]，20世纪40～
70年代，美国和前苏联等国钻了一批试验水平井，由于缺乏经验，应用效果并不好，并一度认为水平井没有经济效益[2]；20世纪70年代末80年代初，此项技术在全世界范围内得到广泛重视，并由此形成了一个研究和应用水平井技术的高潮[3-5]，水平井技术逐渐成为提高油气田单井产量及开发效益最有效的技术手段。

截至2007年底，世界各种水平井总数超过4.5万口，分布在60多个国家和地区[6]。

目前水平井已广泛应用于薄层、低渗透及稠油油藏和气藏等的开发中[7-9]，尤其是近年在页岩气藏开发中的成功应用为世界开发页岩气等非常规资源开辟了新的道路[10]。

我国是世界上第三个能钻水平井的国家，1965年在四川盆地钻成国内第一口水平井——磨3井[11]，此技术应用于塔里木、胜利等油田开发中取得了较好的效果[12-13]。

受制于我国天然气气藏类型复杂及水平井技术不完善等因素，继第一口水平井之后的近40年
里，气藏水平井的开发应用几乎处于停滞状态，规模应用更是近几年才开始。

因此，及时跟踪该项技术的应用动态，总结应用中的经验教训十分必要。

1水平井开发油气藏的优势
水平井，有文献定义为“井斜角大于或等于86°
并保持这种井斜角钻进一定井段后完钻的定向井”[14]，也有定义成“在钻到目的层位时，井段斜度超过85°，水平距离超过目的层厚度10倍的井”[15]，还有定义为“最大井斜角保持在90°左右，并在目的层中维持一定长度的水平井段的特殊井”[16]。

上述定义虽然略有不同，但都明确了水平井必须具备的两层含义：较大的倾斜角和较长的水平段。

水平井技术之所以能够在国内外得到广泛应用，主要得益于它较好的投入产出比。

目前，国外水平井钻井成本已降至直井的1.2～2倍，而产量则是直井的4～8倍[17-19]。

水平井技术作为一项有潜力的新技术，主要有以下优势[1,20-23]：①恢复老井产能。

在停产老井中侧钻水平井较钻调整井或加密井更节约费用，能以较少的投入获得更高的采收率。

/Natural Gas Technology and Economy
天然气技术与经济
Natural Gas Technology and Economy
24
②开发复杂类型油气藏。

水平井在开发重油稠油油藏、以垂直裂缝为主的油气藏、薄油气藏、多层陡峭产层以及边底水活跃储层中具有技术上的优势。

③有利于勘探开发评价。

在勘探阶段，水平井在目的层钻进距离更长，可以更好更多地收集目的层的资料，发现新油气藏；在开发评价阶段，有利于油气田开发井类型的优化，制定科学的开发方案。

④有利于环境保护。

一口水平井可以替代多口直井，从而可以减少用地和钻进过程中对环境的污染。

2国内气藏水平井应用状况及效果分析2005年以后，国内石油公司开展了新一轮水平井开发气藏的先导试验，且应用规模不断扩大。

经过几年的探索及试验，气藏水平井开发技术得到比较全面的提高，并在低渗透砂岩、火山岩、疏松砂岩、碳酸盐岩和凝析气藏的开发中取得一定的效果。

2.1低渗透砂岩气藏水平井开发
低渗透砂岩气藏一般指储层渗透率低、自然产能低、须采取增产工艺措施才能经济有效开发的气藏。

发展有效储层预测、提高单井产量、低成本钻采工艺与地面优化简化技术是经济有效开发此类气藏的关键。

水平井技术作为提高单井产量的有效手段，是开发此类气藏的最主要方式之一。

苏里格气田水平井应用取得阶段性进展，储层钻遇率由早期的25%提高到52%，单井产量也显著提高，如苏10-31-48H井初期日产气为10×104m3，是周围直井的10倍，目前生产稳定。

其他投产井也表现出一定的生产能力，由于生产时间较短，生产效果还需要时间来检验，同时储层钻遇率仍然有较大的提升空间。

川西新场气田属于典型的低渗透砂岩气藏，气田水平井应用一波三折，初期在中浅层开展了4口水平井先导试验，自然产能仅为（0.4～0.8）×104m3／d，与直井相当。

在认识到垂向渗透率的重要性后（垂向渗透率比水平渗透率低2～3个数量级），进行了压裂改造，采取措施后产能达到（2～10.5）×104m3／d。

2.2火山岩气藏水平井开发
我国火山岩气藏资源十分丰富，总资源量超过3×1012m3。

火山岩气藏岩石类型异常繁多，岩性岩相及孔喉结构极其复杂，储层大多表现为低孔低渗的特征，储层连通性差，直井开发往往具有单井产能和井控储量较低的不足。

水平井通过增加与储层的接触面积，连通横向不连通或连通差的储渗体，可以提高单井产能和井控储量，提高气藏整体开发效益。

长岭气田属于中低孔低渗气藏，储层综合评价以Ⅰ类储层为主。

气藏开发设计以水平井开发为主，先期完钻的4口水平井储层平均钻遇率为
91%，获气井3口，目前平均产量为34×104m3／d，单井控制储量增加，如长深平1井动态储量为31×108m3，是周围直井的3.7倍。

徐深气田属于低孔低渗气藏，非均质性强，综合评价以Ⅱ、Ⅲ类储层为主。

完钻水平井储层平均钻遇率为75%，徐深1-平1井试气日产气为13×104m3，徐深1-平2井试气日产气为20×104m3，仅为邻近直井稳定产量的2～3倍。

2.3疏松砂岩气藏水平井开发
该类气藏具有埋藏浅、岩性疏松、气层层数多、气层薄、气水关系复杂等特点，气井出水、出砂和非均匀动用是制约气田开发的关键因素。

台南气田2008年底投产水平井储层平均钻遇率为94%，单井日出水为0.6m3，单井日产气为18.7×104m3，平均试气无阻流量为同层直井的2～2.5倍，水平井在控制出水和提高单井产量方面取得一定的开发效果。

但个别水平井测试产量与直井差别不大，总体上不同储层级别的水平井产量Ⅰ类>Ⅱ类>Ⅲ类，表明水平井开发此类气藏存在明显的选择性。

以Ⅱ、Ⅲ类储层为主的涩北一号和涩北二号气田的气层层数更多、单层厚度更薄、含水更复杂，水平井开发效果更差，涩H5井和涩H6井初期产量分别为邻近直井的1.3倍和0.5倍，水平井大幅度提高单井产量的优势没能体现出来。

2.4碳酸盐岩气藏水平井开发
碳酸盐岩气藏主要分布在塔里木、四川、鄂尔多斯和渤海湾盆地。

靖边气田下古马五段为一套海相碳酸盐岩地层，大面积分布，区域地质构造平缓，厚度稳定，主力气层优势明显，储集空间以裂缝—溶孔为主，
天然气技术与经济·钻井工程
总第25期2011年
天然气技术与经济／25
局部微裂缝发育，这些地质条件较适宜水平井应用，统计的4口试采水平井平均产量为周边直井的
2.3～
3.2倍。

但是，气藏古地貌侵蚀沟槽发育，局部小幅度构造发育复杂，使得井眼轨迹控制难度大，储层钻遇率一直较低，2007年不足20%，2009年也仅为53%。

磨溪气田雷口坡组气藏为层状孔隙性白云岩储层，横向分布稳定，但储层物性差（平均渗透率为0.26mD），直井开发产量低。

采用水平井开发后，储层平均钻遇率为92%，平均单井产量为3.6×104m3／d，为周围直井的2倍，取得一定的效果。

嘉陵江组气藏构造高低部位均见地层水，产层薄，储量丰度低，Ⅲ类储层储量难以动用，造成水平井开发效果差。

完钻井11口，除2口井未投产外，剩余有7口井出水，4口井测试产量低，气藏整体开发效果较差。

2.5凝析气藏水平井开发
国内凝析气藏水平井开发主要在塔里木油田进行，牙哈2-3凝析气藏为块状底水气藏，水平井开发该类气藏具有生产压差小、有效抑制气窜和底水锥进、产量高、稳产期长、采收率高、经济效益显著的优势，适宜凝析油含量高的凝析气藏的高效开发。

已钻水平井4口，其产量是直井的3倍，钻井成本仅为直井的2倍。

2.6水平井技术应用小结
1）低渗透砂岩气藏水平井开发能够较好地克服单井产量低和井控储量少的缺陷，是该类气藏开发的有效手段。

但是气层较薄致使有效储层预测困难，气水关系复杂使钻井面临较大的风险，储层物性差使得水平井不得不进行后期改造，水平井开发面临挑战，其适应性还有待进一步研究。

2）火山岩气藏水平井开发具有明显的选择性，从应用效果看，Ⅰ类储层是成功的，Ⅱ、Ⅲ类储层表现出一定的不适应性，实施效果还有待进一步跟踪观察。

3）疏松砂岩气藏水平井开发效果Ⅰ类好于Ⅱ类，Ⅱ类好于Ⅲ类。

生产效果需要随气井的投产进一步观察评估，及时总结实施情况，做好水平井技术的适应性研究。

从目前的应用效果来看，对该类气藏应慎重选用水平井开发。

4）碳酸盐岩气藏水平井开发过程中，若水平井能够准确钻遇有效储集层，则开发效果一般较好。

但是由于此类气藏储集类型多、气水关系复杂、纵横向非均质严重，水平井钻井常常落空、钻遇非有效储集层、钻遇水层，从而严重影响开发效果。

5）目前国内用水平井开发的凝析气藏储层较好，因此开发效果亦较好。

3气藏水平井技术使用条件及发展建议3.1使用条件
水平井应用规模越来越大，但并不是所有的气田都可以通过钻水平井获得良好的经济效益。

通过对国内气藏水平井开发效果的分析，认为水平井的使用须着重考虑以下几点：
1）储层地质特性和储量规模。

水平井的特点是提高单井产量和单井控制储量，因此相对直井，水平井在开发渗透率低、裂缝发育、单层有效厚度薄、储量丰度低的气藏中具有技术上的优势。

但是，气藏必须具有一定的空间展布，具备一定的储量基础，从而保障水平井开发在较长的时间内经济有效。

2）纵向层数不宜过多。

对于层多且薄的气藏，水平井往往只能控制若干小层，难以构成主力井网。

因此，多层气藏开发时，需要气藏具有主力储层并能准确预测主力储层，否则需要慎重使用水平井。

3）纵向渗透率与水平渗透率差别不宜过大。

直井周围的气体流动表现为平面径向流，而水平井相当于一个躺倒的直井，表现出椭圆流的形态。

若两个方向渗透率差别太大，则水平井的自然产能与直井相差不大。

对于该类储层，需要认识水平井压裂改造的可行性，若可行性较低，则气藏亦不适合采用水平井开发。

4）气水关系简单的块状底水气藏适宜应用水平井开发。

与直井相比，水平井开发该类气藏具有降低生产压差，抑制气窜和底水锥进速度，实现产量高、无水生产期长、采收率高、经济效益好的目的。

实际上，从国内水平井应用情况来看，制约水平井规模应用的因素还比较多。

因此，要结合水平井开发的特点，即延长泄气半径以达到提高单井动用储量、实现高产和稳产，深入研究使用水平井的可行性。

第5卷第1期
孙玉平，等：我国气藏水平井技术应用综述
/Natural Gas Technology and Economy
26
3.2发展建议
1）继续开展水平井应用跟踪及储层适应性研究。

我国水平井规模应用的时间较短，开发中存在的问题可能还没有充分暴露出来，潜在风险依然存在，因此有必要继续跟踪水平井生产动态，客观评价开发效果和使用条件。

尤其是实现水平井规模开发的气田，不能满足于短期的开发成果，而必须密切跟踪开发动态，真正摸索出水平井开发各类储层的适应性。

2）继续开展水平井配套技术研究。

水平井应用是否成功很大程度上取决于配套技术是否完善，例如地质导向技术，国外MWD（随钻测量）和LWD （随钻录井）导向仪器的出现实现了水平井钻井定向，大大提高了中靶准确率和生产井产量，而我国地质导向技术相对不完善，储层钻遇率依然较低。

此外，对水平井欠平衡钻井、气体钻井技术、低损害钻井液钻水平段、水平井分段压裂改造等配套技术还需要进行进一步研究。

3）开展水平井开发经济效益分析。

我国天然气开发对象日趋复杂，水平井开发成本一般为直井的2～2.5倍，为保障气藏开发的经济效益，要求水平井不仅初期产量高，还必须具备一定的稳定生产能力。

工程技术人员要认真做好气藏工程研究，水平井单井产量和稳产分析，水平井投入和产出分析，确保做到气藏开发技术水平高、经济效益好。

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（编辑：卢栎羽）
天然气技术与经济·钻井工程
总第25期2011年
天然气技术与经济／27
ABSTRACTS AND AUTHORS
天然气技术与经济／Natural Gas Supply and Demand Predic ⁃tion for 2015-Advices and Ideas for 12th Five Year Plan
By ZHANG Kang
ABSTRACT:Increasing natural gas supply is the most realistic and powerful way to reach the goal of energy supply in 12th Five Year Plan.According to prediction,China ’s gas consumption will
be 2500×108m 3
by 2015with total energy consumption reaching 40×108tce or 42×108tce,and proportion of natural gas in total pri⁃mary energy reaching 8.3percent or 8.0percent.Among them,do⁃mestic supplies will be around 1500×108m 3and gas imports will be around 1000×108m 3.To achieve this goal,China should make great efforts to keep continuous and rapid growth of unconvention⁃al gas production,diversify supply sources,enhance pipeline gas and LNG imports,accelerate infrastructure facilities co-building along the gas industry system integrating upstream,mid-stream and downstream sectors and promote marketization mechanism re⁃form.
Key Words:natural gas,12th Five Year Plan,structure adjustment,coal-bed methane,shale gas,LNG
Research on Game Theory of Natural Gas Supply Distribution between Gas De ⁃velopment District Governments and Cen ⁃tral Government
By WANG Chuan,CHENG Hong-wei and ZHOU Guo-dong
ABSTRACT:The benefits distribution structure of natural gas de⁃velopment is determined by organizational structure.However,there are all kinds of contradictions existing in current benefits dis⁃tribution structure,among which,contradictions between gas devel⁃opment district governments and central government is getting out⁃standing.To discuss the relationships between on benefits distribu⁃tion,a game model based on game theory is set up.The application of the model with the case of Dazhou natural gas development shows,there are two Nash equilibrium points during the gaming process and which equilibrium point will be achieve is determined by game ability competition between the tow levels of government.Moreover,local governments are suggested to make rational invest⁃ment plan to avoid indiscriminate investment and overinvestment.Key Words:natural gas,government of development district,central government,benefit contradiction,game model
Sequence-stratigraphic Framework and Sedimentary Facies of Badaowa Forma ⁃tion,Sishilicheng Depression
By WANG Mu and LI Xiao-gang
ABSTRACT:In Sishilicheng depression of Yanqi Basin,Bad⁃aowa Formation becomes one of the most important payzones when searching for subtle trap.In this study,the formation is restored through seismic-line description and by 4seismic lines across the depression.And then,the arrange style and reflection termination kind of inner layers and the drilling lithological compound charac⁃teristics are analyzed.Badaowa Formation can be classified into 3sequences.And 4tract systems are also recognized (including low⁃stand tract,transgressive tract system,highstand tract and forced regressive tract system)within these sequences.In addition,some
sedimentary facies belts are presented,including lowstand delta,alluvial fan and channel,based on an analysis of both seismic fa⁃ices and sedimentary facies.The results illustrate that the series foreset developed at forced regressive tract system not only is a re⁃sponse of sandstone interbedded with shale,but also has a poten⁃tial to developing lithological trap.It will be an important target for further exploration.
Key Words:Badaowa Formation,seismic line description,seismic facies and sedimentary facies,lithological trap
Seismic Identification of Fractured Reser ⁃voir
By ZHAO Cheng-liang,LI Rui,DENG Yan,YOU Wen-xiu and HOU Yu
ABSTRACT:In this paper,both pre-stack and post-stack frac⁃ture detection technologies have been applied to a fine description to fracture ’s growth density and azimuth of tight sandstone in western Sichuan Basin.And the distribution of fracture-developed zone is also analyzed.It is very difficult to predict fracture precise⁃ly by only one seismic technology just because of the complexity and multiple-solution of fracture.So,both pre-stack and post-stack fracture detection technologies should be applied to⁃gether to the fine description,which can either indicate a frac⁃ture-developed portion or further show the fractured-developed scale and connectivity.
Key Words:fracture,multiple solution,pre-stack,post-stack,seismic technology
Principles and Practices of Seismic Re ⁃ceiving of Wideline and Large Array
By LUO Ren-ze,HUANG Yuan-yi,ZENG Jun-feng and XU Jin-qiang
ABSTRACT:In some regions with a small signal-to-noise ratio,the quality of seismic profile may not be improved obviously even though many round exploration.One of the most crucial factors is that very developed interference wave makes the acquired sig⁃nal-to-noise ratio very low.In this study,some key parameters of receiving line distance and number,and array receiving area are discussed based on a systematic analysis on wideline and large ar⁃ray receiving principle;a seismic receiving technology of both wideline and large array is presented.This technology has been ap⁃plied to Xinjiang Keche depression and Amute area.It is illustrat⁃ed that the technology can not only inhibit the noise of seismic da⁃ta but also increase the signal-to-noise ratio.In addition,it can be applied to other complex areas with low signal-to-noise ratio and developed interference wave.
Key Words:low signal-to-noise ratio,seismic signal,wideline,large array,array receiving area,acquisition receiving
Review and Suggestion on Application of Horizontal-well Technology to Gas Reser ⁃voirs in China
By SUN Yu-ping,LU Jia-liang,GONG Yu-zheng,HUO Yao and YANG Guang-liang
ABSTRACT:In China,the proportion of low-quality reserves (complicated and difficult to be recovered)is rising constantly along with a deep development of gas E &P.So,it ’s very difficult to have an economic and effective exploitation.At present,horizon⁃
77
tal-well technology is one of the most effective tools to not only re⁃duce an investment of productivity construction but also increase development benefits.This study presents and analyzes some expe⁃riences and lessons from the application of horizontal-well technol⁃ogy to five kinds of reservoir.In addition,it points out that:(1)hori⁃zontal-well technology is one of the most effective tools to economi⁃cally exploit sandstone gas reservoirs with low permeability,and the most important is an adaptability of geological condition;(2)for volcanic-rock gas reservoirs,the application of horizontal-well technology to I type reservoir is successful whereas a certain in⁃adaptability may appear in both II and III type;(3)for loose sand⁃stone gas reservoirs,its application to I type is better than that to II type,and II type better than III type;(4)for carbonate gas reser⁃voirs,the most important to the technology is effective reservoir to be accurately drilled;and(5)for condensate gas reservoirs,the technology’s effect is better.Moreover,its application conditions are summed up based on characteristics and experiences of hori⁃zontal-well technology.At last,some suggestions on analysis are made,including for the adaptability of horizontal-well reservoir, the research and development of matching technologies and the economic benefits.
Key Words:horizontal well,gas reservoir,adaptability,develop⁃ment suggestion,review
Law of Well Deviation Caused by Forma⁃tion Shear Stress in Gas Drilling
By ZHU Hua-shu,YU Rui-qing,WANG Gun,ZHAO Wen and LIAN Zhang-hua
ABSTRACT:The formation build-up rate in gas drilling is differ⁃ent from that in mud drilling because in gas drilling there is no confining pressure and there is a large change existing in anisotro⁃pic data.To have a better understanding of well-deviation law in gas drilling,a rock mechanics model for different drilling patterns has been established by finite-element theory.Considering the in⁃fluence of both different dip angles and circulating medium,this paper calculates rock shear stress,and then finds out the well-de⁃viation law in gas drilling.Results show that under the same engi⁃neering and geological conditions,the build-up rate(about35%) in gas drilling is far greater than that in mud drilling.A deviation may easily take place in gas drilling.When drilling with dip angle below30°,well trajectory should be vertical to inclination;with dip angle of45°,the deviation is not obvious;and with dip angle above60°,well trajectory should be parallel to the inclination. Key Words:gas drilling,well deviation,rock shear stress,dip angle
Detection and Repair for Casing Damage in Deep Wells,Western Sichuan Basin By LIU Wei,LI Li,LI Hui and TAN Wei
ABSTRACT:Deep wells in western Sichuan Basin are featured by deep burial depth,high pressure,high CO2pressure,and long drilling cycle.As a result,casing damage always takes place,espe⁃cially in highly deviated directional and horizontal wells.In this paper,the performance,advantages and disadvantages of four de⁃tecting technologies for the damage are presented,including down⁃hole video,multi-finger caliper logging,ultrasonic and electromag⁃netic damage-detection logging;and then,six repair technologies are put forward,including casing shaping,removing and replace⁃ment,sidetracking,casing patch,reinforcement and automatic ren⁃ovation of pneumatic casing.Based on the high pressure and yield of deep wells,it suggests that quantitative detection using multi-finger caliper should be applied to casing-damage wells, and casing patch or sidetracking should be used for repair.
Key Words:casing damage,deep well,western Sichuan Basin, multi-finger caliper,electromagnetic damage-detection logging Application of Hydraulic Sand Fracturing to Sulige Gasfield
By YANG Ya-dong,LIAO Kuo and LI Bin
ABSTRACT:In Sulige gasfield,there are many technical prob⁃lems existing in hydraulic sand fracturing,such as fracturing-fluid optimization,proppant selection,program-parameter determina⁃tion and liquid flowback.In this paper,one problem which empha⁃sizes the poor effect of sand fracturing on the gasfield is fully stud⁃ied;the fracturing-fluid formula,proppant,and optimized fluid configuration program,which are suitable to the block,have been optimized;and the thoughts on hydraulic fracturing,including mod⁃erate scale,small flow rate,long-fracture building,reasonable sand concentration,and finite conductivity,are put forward by FroPt2007software.Through a field test,the production in both Tao7-8-5and Tao7-9-14wells has greatly increased and an ob⁃vious effect is achieved.
Key Words:Sulige gasfield,hydraulic sand fracturing,fracturing fluid,proppant,fracturing design,flowback after compression Water-base Heat-sensitivity Barite Plug⁃ging and Its Application
By ZHANG Kun,XU Ying,HUANG Ping,ZHANG Yuan-bin,AN Li,ZHENG Jian-kun,LI Jian-hui and CHEN Shi-zhong ABSTRACT:Some complex situations including blowout and lost circulation may take place during drilling certain well section with multi pressure systems,which affects severely a safety drilling.So far,there are always two methods to overcome this problem,such as conventional compound plugging and slurry plugging.However, for these two methods,there are many disadvantages of low suc⁃cess ratio and poor effect in primary plugging,and flash condensa⁃tion of slurry plugging easily occurring in some deep wells or cer⁃tain wells with high density.In this study,a technology of wa⁃ter-base heat-sensitivity barite plugging is presented,and its mechanism is also analyzed;and then,some corresponding aspects of the affecting factor,formula,plugging condition and intensity are studied in lab;at last,the technology,characterized by strong heat sensitivity,fast plugging,high intensity,controllable plugging thickness and simple operation,forms.In addition,its application to both Jianmen1and Longgang001-27wells obtains a better ef⁃fect.This technology can solve both upper-blowout-lower-circula⁃tion and lower-blowout-upper-circulation.
Key Words:water base,heat sensitivity,barite plugging, plugging technology,property evaluation,experiment,application effect
Safety Criterion of Percussive Borehole Vibration to Buried Pipeline
By SONG Chun-sheng,LI Peng-fei and PU Chuan-jin ABSTRACT:In order to determine the criterion of the effect of non-explosive vibration caused by percussive borehole on buried gas pipeline during pile foundation construction,and to guarantee the safety operation of pipeline,this study analyzes the explosive vibration,mechanical vibration,seismic fortification intensity and the Pile Foundation Engineering Manual in China and the vibra⁃tion safety criterion in Swiss at first;and then analyzes the safety criterion of percussive borehole vibration to buried pipeline.The
/Natural Gas Technology and Economy 78。