CN107352862A - 耐温型抗水侵凝胶水泥浆 - Google Patents

耐温型抗水侵凝胶水泥浆 Download PDF

Info

Publication number
CN107352862A
CN107352862A CN201710425976.7A CN201710425976A CN107352862A CN 107352862 A CN107352862 A CN 107352862A CN 201710425976 A CN201710425976 A CN 201710425976A CN 107352862 A CN107352862 A CN 107352862A
Authority
CN
China
Prior art keywords
monomer
water resistant
heat
cement slurry
invades
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN201710425976.7A
Other languages
English (en)
Other versions
CN107352862B (zh
Inventor
刘景丽
李立昌
任强
马骏
刘泸萍
张雅静
黄建
郑保东
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
China National Petroleum Corp
CNPC Bohai Drilling Engineering Co Ltd
Original Assignee
CNPC Bohai Drilling Engineering Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by CNPC Bohai Drilling Engineering Co Ltd filed Critical CNPC Bohai Drilling Engineering Co Ltd
Priority to CN201710425976.7A priority Critical patent/CN107352862B/zh
Publication of CN107352862A publication Critical patent/CN107352862A/zh
Application granted granted Critical
Publication of CN107352862B publication Critical patent/CN107352862B/zh
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B28/00Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements
    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B24/00Use of organic materials as active ingredients for mortars, concrete or artificial stone, e.g. plasticisers
    • C04B24/16Sulfur-containing compounds
    • C04B24/161Macromolecular compounds comprising sulfonate or sulfate groups
    • C04B24/163Macromolecular compounds comprising sulfonate or sulfate groups obtained by reactions only involving carbon-to-carbon unsaturated bonds
    • CCHEMISTRY; METALLURGY
    • C08ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08FMACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F220/00Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride ester, amide, imide or nitrile thereof
    • C08F220/02Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
    • C08F220/52Amides or imides
    • C08F220/54Amides, e.g. N,N-dimethylacrylamide or N-isopropylacrylamide
    • CCHEMISTRY; METALLURGY
    • C09DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09KMATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K8/00Compositions for drilling of boreholes or wells; Compositions for treating boreholes or wells, e.g. for completion or for remedial operations
    • C09K8/42Compositions for cementing, e.g. for cementing casings into boreholes; Compositions for plugging, e.g. for killing wells
    • C09K8/426Compositions for cementing, e.g. for cementing casings into boreholes; Compositions for plugging, e.g. for killing wells for plugging
    • CCHEMISTRY; METALLURGY
    • C09DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09KMATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K8/00Compositions for drilling of boreholes or wells; Compositions for treating boreholes or wells, e.g. for completion or for remedial operations
    • C09K8/42Compositions for cementing, e.g. for cementing casings into boreholes; Compositions for plugging, e.g. for killing wells
    • C09K8/46Compositions for cementing, e.g. for cementing casings into boreholes; Compositions for plugging, e.g. for killing wells containing inorganic binders, e.g. Portland cement
    • C09K8/467Compositions for cementing, e.g. for cementing casings into boreholes; Compositions for plugging, e.g. for killing wells containing inorganic binders, e.g. Portland cement containing additives for specific purposes
    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2111/00Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
    • C04B2111/20Resistance against chemical, physical or biological attack
    • C04B2111/27Water resistance, i.e. waterproof or water-repellent materials
    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2201/00Mortars, concrete or artificial stone characterised by specific physical values
    • C04B2201/20Mortars, concrete or artificial stone characterised by specific physical values for the density

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Organic Chemistry (AREA)
  • Ceramic Engineering (AREA)
  • Materials Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Structural Engineering (AREA)
  • Inorganic Chemistry (AREA)
  • Health & Medical Sciences (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Curing Cements, Concrete, And Artificial Stone (AREA)
  • Soil Conditioners And Soil-Stabilizing Materials (AREA)

Abstract

本发明公开了一种耐温型抗水侵凝胶水泥浆,包括G级油井水泥、调节剂、缓凝剂、分散剂和填料;G级油井水泥和填料的质量比为1:0.6~1;以G级油井水泥和填料的质量和为基准,调节剂、缓凝剂、分散剂占其质量百分比为8~16%、0~2%和0~1%;调节剂通过如下方法制得:先将氢氧化钠溶于水中,散热后,加入单体,除氧后,加入引发剂,在50~65℃条件下反应3~4h,冷却至室温;其中,单体为N,N二甲基丙烯酰胺单体、丙烯酰胺单体、2‑丙烯酰胺基‑2‑甲基丙磺酸单体和丙烯酸单体的混合物。该水泥浆在高温下具有很好的抗水稀释能力,在水中不易分散,不易被地层水污染,可根据施工时间调节水泥浆稠化时间,封堵地层。

Description

耐温型抗水侵凝胶水泥浆
技术领域
本发明属于石油钻井工程、煤层气工程领域,特别是涉及一种耐温型抗水 侵凝胶水泥浆。
背景技术
目前,油田在堵水调剖、层漏所用堵剂主要存在下列问题:1)有机堵剂的 封堵浆体固结后强度不佳,抗温能力不够,有效期短;而强度大、封堵效果好 的堵剂成本高,不适合大剂量封堵施工。2)无机堵剂中的石灰乳成本低,是国 内最通用的技术,但石灰乳在水中易被水冲释,抗水侵能力差,反应时间不易 控制,颗粒大易沉降井底,对储层伤害性较大;超细水泥存在波及体积小,施 工安全不好保证的技术难点,不能有效地驻留在封堵层位,堵剂替至目的层后 未凝固前就已漏失掉,造成堵浆注入量大,施工时间长。
在钻井过程中经常遇到地层中存在暗河、断层放空等情况,造成严重漏失。 解决这种漏失问题,常规钻井液堵漏无效,水泥堵漏因易被稀释,也会发生堵 漏失败。一旦堵漏失败,一是造成钻井复杂,二是有的暗河和当地水源相通, 会造成污染引起环保事故。
在井下作业水泥打塞封堵目的层时,由于井下存在地层水、盐水层或已被 污染水源,水泥浆在泵送过程中易被冲释、稀释,可能对水泥浆造成污染导致 水泥浆长时间不凝固,需要进一步打二次塞,甚至打三次塞,增加施工周期。
发明内容
为了解决上述技术问题,本发明提供一种耐温型抗水侵凝胶水泥浆,该耐 温型抗水侵凝胶水泥浆在高温下具有很好的抗水稀释能力,在水中不易分散, 不易被污染,可根据施工时间调节水泥浆稠化时间,封堵地层。
为此,本发明的技术方案如下:
一种耐温型抗水侵凝胶水泥浆,包括G级油井水泥、调节剂、缓凝剂、分 散剂和填料;
所述G级油井水泥和填料的质量比为1:0.6~1;
以所述G级油井水泥和填料的质量和为基准,所述调节剂、缓凝剂、分散 剂占其质量百分比分别为8~16%、0.5~2%和0~1%。
进一步,所述填料为高炉矿渣、粉煤灰、微珠、坂土和增强剂PZW中的一 种或任意两种的混合物。
进一步,所述调节剂通过如下方法制得:
1)将氢氧化钠溶于水中,散热后,得到氢氧化钠水溶液;
2)将单体溶解于氢氧化钠水溶液中,除氧后,加入引发剂,在50~65℃条 件下反应3~4h,冷却至室温,即得调节剂;
其中,所述单体为N,N二甲基丙烯酰胺单体、丙烯酰胺单体、2-丙烯酰胺 基-2-甲基丙磺酸单体和丙烯酸单体的混合物;
所述N,N二甲基丙烯酰胺单体的质量占所述单体质量的50~60%;
所述丙烯酰胺单体的质量占所述单体质量的5~12%;
所述2-丙烯酰胺基-2-甲基丙磺酸单体的质量占所述单体质量的18~22%;
所述丙烯酸单体的质量占所述单体总质量的15~17%;
所述引发剂的质量为所述单体质量的0.3~0.5%;优选,引发剂是氧化-还 原体系:过硫酸钾-偏重亚硫酸钠(摩尔比为1:0.5~0.8);
所述氢氧化钠水溶液中,所述氢氧化钠的物质的量为所述2-丙烯酰胺基-2- 甲基丙磺酸单体和丙烯酸单体的物质的量之和;
水的质量为所述单体质量的2.5~3倍。
进一步,所述缓凝剂为多羟基羧酸和磺酸盐的混合物,耐温180℃,具体可 以为中国石油渤海钻探工程技术研究院生产的ZH-6型缓凝剂。
进一步,所述分散剂为磺化丙酮-甲醛缩聚物,购自河南省卫辉市油田化学 有限公司。
本申请提供的技术方案是从油井水泥角度出发,为提高水泥浆在高温段的 抗水侵能力研发一种在水中不易分散的堵水堵漏专用凝胶水泥浆体系。该水泥 浆体系在高温下具有很好的抗水稀释能力,在水中不易分散,不易被污染,可 根据施工时间调节水泥浆稠化时间,封堵地层。
工作原理:该凝胶水泥通过研发一种耐温型调节剂,利用其增加水泥浆在 高温下的粘度,来提高水泥浆在高温下的抗水侵性能,使油井水泥、填料及其 它助剂所形成的凝胶水泥浆体系在100℃~160℃具有很好的锁水性,在水中不 易被水冲释。
具体实施方式
以下结合实施例对本发明的技术方案进行详细描述。
实施例1
调节剂的制备:先将氢氧化钠12.18g溶于250mL水中,散热后将N,N二甲 基丙烯酰胺单体60g、丙烯酰胺单体5g、2-丙烯酰胺基-2-甲基丙磺酸单体20g、 丙烯酸单体15g溶于氢氧化钠水溶液中,搅拌除氧,在55℃下加入氧化-还原引 发剂体系(过硫酸钾0.3g,偏重亚硫酸钠0.11g)反应3h冷却至室温。
耐温型抗水侵凝胶水泥浆1:
G级油井水泥250g+粉煤灰250g+本实施例制得的调节剂40g+水275mL+表 1中质量的缓凝剂,缓凝剂选用中国石油渤海钻探工程技术研究院生产的ZH-6 型缓凝剂。
表1实施例1中耐温型抗水侵凝胶水泥浆1性能测试结果
耐温型抗水侵凝胶水泥浆2:
G级油井水泥155g+超细矿渣155g+坂土40g+本实施例得到的调节剂55g+ 水500mL
表2实施例1中凝胶水泥浆配方2性能测试结果
实施例2
调节剂的制备:先将氢氧化钠13.49g溶于300mL水中,散热后将N,N二甲 基丙烯酰胺单体50g、丙烯酰胺单体12g、2-丙烯酰胺基-2-甲基丙磺酸单体21g、 丙烯酸单体17g溶于氢氧化钠水溶液中,搅拌除氧,在60℃下加入氧化-还原引 发剂体系(过硫酸钾0.3g,偏重亚硫酸钠0.11g)反应3.5h冷却至室温。
耐温型抗水侵凝胶水泥浆3:
G级油井水泥360g+微珠80g+增强剂PZW40g+本实施例制得的调节剂40g+ 分散剂4.8g+水272mL+表3中质量的缓凝剂,缓凝剂选用中国石油渤海钻探工 程技术研究院生产的ZH-6型缓凝剂。
表3实施例2中耐温型抗水侵凝胶水泥浆3性能测试结果
以实施例2制得的调节剂为例,调节剂加量变化对凝胶水泥浆性能的影响:
耐温型抗水侵凝胶水泥浆4:
G级油井水泥250g+粉煤灰250g+本实施例制得的调节剂0~40g+水 272mL+缓凝剂6g,缓凝剂选用中国石油渤海钻探工程技术研究院生产的ZH-6 型缓凝剂。
表4实施例2中耐温型抗水侵凝胶水泥浆4性能测试结果
调节剂加量对凝胶水泥性能影响主要是体系的抗水侵性能,不加调节剂, 水泥浆体系没有抗水侵效果,遇水则呈云雾状分散开,加入调节剂后水泥浆体 系即为凝胶水泥浆体系具有一定的抗水侵效果,调节剂加量越大抗水侵性能越 优良,但同时凝胶水泥浆的流动性能变差,现场施工要兼顾水泥浆的抗水侵性 能又要使水泥浆体具有较好的流动性,所以调节剂的加量要控制在合理范围内, 以实施例2制得的调节剂为例,调节剂加量占油井水泥及填料总重的6~8%、 水泥浆体流动度控制在≥18cm最佳。

Claims (9)

1.一种耐温型抗水侵凝胶水泥浆,其特征在于:包括G级油井水泥、调节剂、缓凝剂、分散剂和填料;
所述G级油井水泥和填料的质量比为1:0.6~1;
以所述G级油井水泥和填料的质量和为基准,所述调节剂、缓凝剂、分散剂占其质量百分比分别为8~16%、0~2%和0~1%;
所述调节剂通过如下方法制得:
1)将氢氧化钠溶于水中,散热后,得到氢氧化钠水溶液;
2)将单体溶解于氢氧化钠水溶液中,除氧后,加入引发剂,在50~65℃条件下反应3~4h,冷却至室温,即得调节剂;
其中,所述单体为N,N二甲基丙烯酰胺单体、丙烯酰胺单体、2-丙烯酰胺基-2-甲基丙磺酸单体和丙烯酸单体的混合物。
2.如权利要求1所述耐温型抗水侵凝胶水泥浆,其特征在于:所述N,N二甲基丙烯酰胺单体的质量占所述单体质量的50~60%;
所述丙烯酰胺单体的质量占所述单体质量的5~12%;
所述2-丙烯酰胺基-2-甲基丙磺酸单体的质量占所述单体质量的18~22%;
所述丙烯酸单体的质量占所述单体总质量的15~17%。
3.如权利要求1所述耐温型抗水侵凝胶水泥浆,其特征在于:所述引发剂的质量为所述单体质量的0.3~0.5%。
4.如权利要求1所述耐温型抗水侵凝胶水泥浆,其特征在于:所述引发剂是氧化-还原体系:过硫酸钾-偏重亚硫酸钠,过硫酸钾与偏重亚硫酸钠的摩尔比为1:0.5~0.8。
5.如权利要求1所述耐温型抗水侵凝胶水泥浆,其特征在于:所述氢氧化钠水溶液中,所述氢氧化钠的物质的量为所述2-丙烯酰胺基-2-甲基丙磺酸单体和丙烯酸单体的物质的量之和;
水的质量为所述单体质量的2.5~3倍。
6.如权利要求1~5中任意一项所述耐温型抗水侵凝胶水泥浆,其特征在于:所述填料为高炉矿渣、粉煤灰、微珠、坂土和增强剂PZW中的一种或任意两种的混合物。
7.如权利要求1~5中任意一项所述耐温型抗水侵凝胶水泥浆,其特征在于:所述缓凝剂为多羟基羧酸和磺酸盐的混合物,耐温180℃。
8.如权利要求7中所述耐温型抗水侵凝胶水泥浆,其特征在于:所述缓凝剂为中国石油渤海钻探工程技术研究院生产的ZH-6型缓凝剂。
9.如权利要求1~5中任意一项所述耐温型抗水侵凝胶水泥浆,其特征在于:所述分散剂为磺化丙酮-甲醛缩聚物。
CN201710425976.7A 2017-06-08 2017-06-08 耐温型抗水侵凝胶水泥浆 Active CN107352862B (zh)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201710425976.7A CN107352862B (zh) 2017-06-08 2017-06-08 耐温型抗水侵凝胶水泥浆

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201710425976.7A CN107352862B (zh) 2017-06-08 2017-06-08 耐温型抗水侵凝胶水泥浆

Publications (2)

Publication Number Publication Date
CN107352862A true CN107352862A (zh) 2017-11-17
CN107352862B CN107352862B (zh) 2019-09-06

Family

ID=60272350

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201710425976.7A Active CN107352862B (zh) 2017-06-08 2017-06-08 耐温型抗水侵凝胶水泥浆

Country Status (1)

Country Link
CN (1) CN107352862B (zh)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111234103A (zh) * 2020-03-30 2020-06-05 天津萨恩斯石油技术有限公司 一种降低油井含水率的凝胶聚合物材料及其制备方法
CN111268953A (zh) * 2019-10-12 2020-06-12 四川光亚聚合物化工有限公司 凝胶水泥、缔合聚合物及制备方法

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105061661A (zh) * 2015-08-06 2015-11-18 中国石油集团渤海钻探工程有限公司 油井水泥用中高温缓凝剂及其制备方法

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105061661A (zh) * 2015-08-06 2015-11-18 中国石油集团渤海钻探工程有限公司 油井水泥用中高温缓凝剂及其制备方法

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111268953A (zh) * 2019-10-12 2020-06-12 四川光亚聚合物化工有限公司 凝胶水泥、缔合聚合物及制备方法
CN111234103A (zh) * 2020-03-30 2020-06-05 天津萨恩斯石油技术有限公司 一种降低油井含水率的凝胶聚合物材料及其制备方法

Also Published As

Publication number Publication date
CN107352862B (zh) 2019-09-06

Similar Documents

Publication Publication Date Title
CN101885591B (zh) 一种聚合物型水玻璃固化剂及在水玻璃类化学灌浆材料中的应用
KR100906459B1 (ko) 수화 속도를 조절한 시멘트 그라우트재 및 그의 제조방법
JP5399573B2 (ja) セメント系深層混合処理用添加剤及びこの添加剤を用いたセメント系深層混合処理改良体の造成方法
KR100869467B1 (ko) 지반 개량재용 조성물, 그것을 사용한 주입재 및 그 사용방법
JP4813822B2 (ja) アンカー素子定着材用急硬性セメント組成物、アンカー素子定着材及びアンカー素子の定着方法
CN105062439B (zh) 一种高强度低密度管外封窜剂及其制备方法
Zhang et al. A pasty clay–cement grouting material for soft and loose ground under groundwater conditions
CN103614123A (zh) 一种聚乙烯亚胺冻胶调剖堵水剂
WO2013120636A1 (en) Use of terpolymers as fluid loss additives in well cementing
CN102585788B (zh) 一种过饱和氯化钠固井水泥浆体系
CN107500597A (zh) 一种水下不分散混凝土外加剂及其制备方法
CN107352862B (zh) 耐温型抗水侵凝胶水泥浆
CN103742172B (zh) 一种底板注浆封堵硫化氢突水点的方法
CN103045215B (zh) 一种固井用铝酸盐水泥基耐二氧化碳腐蚀水泥体系
CN105175628A (zh) 一种与amps-ia缓凝剂配伍型油井水泥降失水剂及制备方法
CN107325799A (zh) 一种油井水泥用丙烯酸类降失水剂及其制备方法和应用
CN102533235B (zh) 一种油井水泥中高温早强剂
JP6529821B2 (ja) 地盤安定化用粉体混和剤、地盤安定化材料、及びそれを用いた地盤安定化工法
CN110305641A (zh) 一种改性降失水剂
KR101473228B1 (ko) 고강도 급결성 고화제 조성물
CN107540260A (zh) 一种固井用低温水泥早强剂及包含它的水泥
CN103613351A (zh) 一种固化盐渍土制备方法
CN102531443B (zh) 早强剂组合物及其制备、水泥组合物以及用途
CN107474809A (zh) 一种酸溶性水泥类暂堵剂及其制备方法
Jefferis Long term performance of grouts and the effects of grout by-products

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant
TR01 Transfer of patent right

Effective date of registration: 20231207

Address after: 100007 No. 9 North Main Street, Dongcheng District, Beijing, Dongzhimen

Patentee after: CHINA NATIONAL PETROLEUM Corp.

Patentee after: CNPC Bohai Drilling Engineering Co.,Ltd.

Address before: 300457 Tianjin Binhai New Area Development Zone Second Avenue 83, China Petroleum Tianjin building Bohai Drilling Engineering Co., Ltd.

Patentee before: CNPC Bohai Drilling Engineering Co.,Ltd.

TR01 Transfer of patent right