50.8mm连续油管作速度管串在天然气井的应用.pdf

[ 作者简介] 卢秀德, 男, 1976年出生, 工程师, 2000年毕业于大庆石油学院石油工程专业, 现主要从事连续油管技术工作。 50. 8mm 连续油管作速度管串在天然气井的应用 卢秀德 1 刘 刚 1 杨光炼 2 1. 川庆钻探工程有限公司井下作业公司 四川成都 610051; 2. 川庆钻探工程有限公司钻采工艺技术研究院 四川成都 610051 摘要 随着气井进入开采后期, 地层能量有限, 气水同产井和井筒内原有生产管串等因素的影 响, 严重制约着气井的后期生产, 常规的压井修井作业会导致该井被压死而停产。为充分挖掘老井 潜能, 降低风险程度, 使用连续油管作速度生产管串, 减少气液滑脱损失。分析了国内首次使用 50. 8 mm 连续油管在作速度管串时的计算依据、 现场作业配置和作业效果。这一新工艺已逐步成 为现场气井改造的发展方向。 关键词 连续油管 速度管串 天然气井 应用 引 言 川渝地区石炭系气藏井比较深, 开采期间部分 井产水, 地层压力系数降低, 气水滑脱现象严重, 气 量稳产难度大。针对这些气藏构造特点和开发过程 中存在的问题, 应用连续油管作速度生产管串工艺 技术, 可以避免修井作业带来的复产困难风险, 提高 单井产量、 降低开发成本、 提高储量动用程度。 速度管串工艺设计 一口井实施连续油管作速度管串工艺, 需要进 行流速的计算来确定使用何种规格的连续油管及其 下深情况, 设计配置与工艺相匹配的连续油管井口 悬挂装置和地面流程。 1. 计算临界流速 对于井口压力超过 7 MPa, 可通过泰勒关系式 进行计算。对于井口压力低于 3. 5 MPa 的情况, 可 通过下面的公式计算。 举升凝析气或水的最小临界流速 Vg 为 Vg气 [ 1. 2 45- 0. 45P 0. 25 ] [ 0. 45P 0. 5] 1 Vg水 [ 1. 7 67- 0. 45P 0. 25 ] [ 0. 45P 0. 5] 2 式中 Vg 临界流速,m s; P 井的地面流压, MPa。 某一流通面积 A 的临界气流量 Qg 可通过 下式计算得出 Qg 48PVgA [ T 504 Z] 3 式中 Qg 临界气流量,m 3 d; A 流通面积, m 2; T 地面温度, ; Z 压缩因子, 无因次量纲。 由上面公式则可计算生产油管内可选择的最大 连续油管外径尺寸, dti [ Qg T 504 Z 37PVg ] 0. 5 4 2. 深度极限设计 在垂直井内, CT 下放深度按 CT 重量悬空时载 荷 80 的安全系数来设计。 悬挂长度极限通常由当前 CT 载荷能力决定 Le L80W 5 式中 Le 管串等效长度, m; L80 目前油管载荷的 80, kg 如最大屈 服强度的 80 , 对于使用过的 CT 取 30 至 80, 取决于管串的历史和作业情况 ; W 油管的重量, kg m。 一些用于井筒充液情况的速度管串, 液体浮力 对 CT 极限下深的影响明显。 如果井筒充满液体, 在 浮力作用下 CT 的最大长度 Lb计算式变为 Lb L80 [ 12 r - rm ] 6 2010 年 6月油 气 井 测 试第 19 卷 第 3期 式中 r 油管悬空时密度, g cm 3; rm 流体密度, g cm 3。 3. 井口连续油管悬挂器 连续油管完井既可采取悬挂在现有总闸上, 又 可以用于新式的整装井口悬挂。某些悬挂器要求切 断并通过外置卡瓦悬挂, 而某些悬挂器则要求在悬 挂头外侧由螺栓推动卡瓦来实现。选择悬挂方式应 考虑该井可能持续的生产时间以及存在其它修井作 业的可能性。 4. 地面流程配置 由于在原有的生产管柱内又下入一定规格的连 续油管作速度生产管柱, 增加了地层流体返出通道, 有些井可实现连续油管以及连续油管与原生产管柱 间的小环空合产, 因此地面流程也需与地层流体的 开采方式相匹配。 现场应用 1. 施工井例 GA002H1 2 井 2007 年 09月 07 日完钻, 完钻井 深 3150 m, 2008 年 5 月套压 13. 0 MPa, 油压 6. 8 MPa, 日产气 4 10 4m3 左右, 日产水 9 m 3, 日产油 0. 3 t。井内管串为 114. 30 mm 油管下深 2902 m。开采 至2009 年 3 月, 日产气量衰减至原来的一半, 且一 直产水。2009 年3 月 27日, 采用外径 50. 8 mm 的等 径连续油管1992 m 作速度生产管串, 作业后排水采 气效果明显 见图 1 。 从图1 可以看出 作业前该井产气量为2. 0 2. 2 10 4m3 d, 产水平均为 3 m3 d, 作业后, 产气量增至 3. 0 10 4m3 d, 产水量均值增大为 5. 5 m3 d, 且仍然 有增长趋势。下放 50. 8mm 连续油管作速度生产管 串目的就是减少滑脱损失, 尽可能携带地层水至地 面, 防止产层水淹停产。 2. 现场的配置 连续油管作速度生产管串在现场作业程序包括 连续油管悬挂器安装的位置确定和准备, 连续油管 作业设备的安装, 连续油管的下放程序, 连续油管的 悬挂程序, 连续油管下放到目的深度时的切割, 采气 井口和输出端的合理连接, 以及连续油管自由端塞 子的泵出。连续油管悬挂器采用 WCP 公司生产的 RH3 型装置。 3. 经济效益和风险评估 连续油管作为速度管串用于气井改造时, 最大 特点为 带压作业, 无须对作业井进行压井作业, 避 免常规修井作业将井压死的风险; 成本低, 施工周期 短, 投资见效快。 结 论 国内连续油管作速度管串在 2008 年大面积推 广应用, 但此次采用 50. 8 mm 连续油管在 114. 3 mm 生产油管内作速度生产管串在国内属第一次, 依据 作业井的基本条件进行作业前的计算和分析, 设计 和应用时需充分考虑以下几点 1. 井筒内环境因素, 包括作业前井的基本情况、 地层流体特点等; 2. 连续油管材质的合理选取和参数的设计; 3. 井口连续油管悬挂器的配置; 4. 分析预测连续油管在井筒内失效的可能情 况。 总之, 连续油管作为速度管串用于现场的最大 特点就是, 成本低, 无须压井作业, 能有效控制并降 低气液滑脱损失。该项作业技术的合理采用, 为今 后低产气井后期改造有效开采而提供宝贵经验。 参 考 文 献 [1] George E. King. Designing a Velocity String for Unloading a Gas Well. Reel Reporter, Vol. 7, 2002. [2] Bharath Rao. Multiphase Flow Models Range of Applicability. CTES, 1998. [3] 李宗田. 连续油管技术手册. 石油工业出版社, 2008. 09. [4] 石油工程师学会编. 连续油管技术. 石油工业出 版社, 2000. 11. 本文收稿日期 2009- 12- 08 编辑 方志慧 45 第 19卷 第3 期卢秀德等 50. 8mm 连续油管作速度管串在天然气井的应用 home and abroad, a model of intelligent systems is designed. Through computer program and withthe iterative algorithm, the model calculates the optimal displacement of producing oil wells and oil testing wells, sending orders automatically to make gas inject with the best displacement and monitoring oil pressure at whole period. If the well achieves selfflowing, gas lift stops. if intermittent flowing appears, the intermittent gas lift is done and if not flowing, then the whole gas lift is done. The oil test by gas lift and intelligent control system for producing oil well has features of being automatic precision and control at the whole period, which has practical value to realize maximize efficiency and the lowest cost of the gas lift. Key words intelligent control, gas lift, displacement, monitoring and controlling New Testing and Perforation Technology and Its Application. 2010, 193 41 43 Xu Yadong, ChenHaibo, Fang Yong, Li Jiang Well Testing Company, Bohai Drilling and Exploration Corporation, Sun xuemei Bohai Drilling and Exploration Corporation, DownHole Operation Department Three new technologies of combed operation of multi level pulse composite perforation and tests, super positive for perforation associated with test and the negative pressure opening perforation have been introduced and , a reasonable string structure is recommended , each characteris tic is sum up. Its feasibility, stability and effectiveness are proved by field application. Key words combinedoperation of perforation and test, multilevel pulse composite perforation, inducedflow by negative pressure, Overpres sure perforation Applying50. 8mm Coiled Tubing to Be Speeding String in Gas Well. 2010, 193 44 45 Lu Xiude, Liu Gang Down hole operation department, Sichuanchangqing drilling and exploration engineering company , Yang Guanglian Drilling and production tech research institute, Sichuanchangqing drilling and exploration engineering company Along with limitation of ation energy at later time of exploitation of gas well, influence by factors of wells of producing gas and water of er production string, it sustains production of gaswells seriously and conventionworkover by killing well willmake the wellto stop produce gas. To excavate potential capacity and low risk content, applying coiled tubing to be speeding string in gas well reduces gas and fluid surge lose. Calculating foundation, field operation collocation and operation result of it is analyzed and introduced at the first time. This new tech is to be developing orientation of reation for gas well progressively. Key words coiled tubing, speeding string, nature gas, application Technology of Reducing Operating Fracture Pressure for the Reservoir with Abnormal Breakdown Pressure. 2010, 193 46 48 Zheng Bintao, Guo Jianchun Oil and Gas Reservoir Geology and Exploitation, National Key Laboratory SouthWest Petroleum University The abnormal fracture pressure reservoir is buried deep, whose lithology is dense, tectonic stress is strong, pore pressure is high and reservoir damage is serious, breakdown pressure and fracture extension pressure is high, which causes excessive pressure operating on the ground and more difficult, a high demand on the reservoir re equipment, string and process is put forward at the same time. Fromtwo aspects of Res ervoir geological and engineering factor, the causes of the abnormal breakdown are analyzed and measures of applying acidification pretreat ment, perforating optimization, increased the fracturing fluid, reducing friction to reduce operating pressure are proposed which provides a technical basis for fracturing of the reservoir layer with abnormal breakdown pressure. Key words abnormal breakdown pressure, fracturing, operating pressure, acidification pretreatment, increased the fracturing fluid, friction Thinking of Well Test to Layer of Leng 90 Well. 2010, 19 3 49 51 Ji Shuling, Mo Shangxian, Chen Zhong, Zhao Youdao Qinghai Oil Field, DownHole Operation Department , Liu Xiaozhong Qinghai Oilfield, No. 2 Oil Production Plant , Lu Qigao Qinghai OilfieldTraining Center Leng90 well is an exploration well at the 5th structure of the Qaidam basin, whose layer was tested inNovember 4 to 24, 2008. Complex situations of gas breaking through at annulus, being unclear of open state of testing valve, failure of casting bar to hit reverse circulating pin, communication channel of killing fluid not being established appeared one after another. It is analyzed of selecting tools for gas test, response to packer being unsealing and problems of test to the layer and the response and improvement direction is proposed. Key words well test, problem, discussion Combined Tech of Perforation and Fracturing for Low Permeability Testing Layer in Karamay Oilfield. 2010, 193 52 53 Li Xuebin, Xu Jiangwen, Hu Guangjun Xinjiang Oilfield Exploration Company, Ye Yunqing Xinjiang Oilfield Company Department In order to reduce safety risk of test for nature gas, accelerate the progressof gas test, reduce gas pollution, the combined operation of throwing the gun perforating and fracturing, the full bore hole perforation and fracturing are applied successfully inKaramay oilfield. Field application of them is better and is proposed to promote the use of them in low permeability testing layer at where oil and gas show better. Key words perforation, oil test, fracturing, application Practice of Water Jet Directional Drilling Technology and Its Theory. 2010, 193 54 55, 57 Wang Qingchuan, Wang Yiguo, HuangJianqiang, Zhang Guangjun, Ye Zhenzhong, Li Jianguo, Liu Zimeng Huabei Oilfield Company, the Fourth Oil Production Plant Operating Unit The water jet technology uses coiled tubing directional drilling and water injection technology to achieve the drilling of the target layer which is the new model of increasing production technology, has advantages of directional drilling and deep penetration. The principle and main tools are introduced and the technical process is illustrated by examples. Key words water jet, coiled tubing, drilling, application Application of Combined Tech of Hydraulic Pump with Fracture in Changqing Oilfield for Low Pressure, Low Permeability Reser voir. 2010, 193 56 57 Zhu Tie, Xue Qingxiang Dagang Oilfield, Drilling productionresearch institute , Li Wuping, Chen Wanlin DownHole Service Compa ny, Chuanqing Drilling and Exploration Engineering Co. , Ltd 77 2010年 6 月油气井测试