摘要
巴彦河套盆地储层低成熟度、高渗透、低强度、高泥质含量特性显著,井壁岩性水敏性强,地层不稳定而易垮易漏,固井面临井深、封固段长、顶替效率低、界面胶结差和后期压裂对水泥环力学性能要求高等技术难题,采用界面增强材料DRJ-2S、膨胀增韧材料DRE-4S等固井关键材料,形成了综合性能良好的DRJ-2S批混批注固壁型冲洗隔离液和DRE高强度韧性微膨胀水泥浆体系。研究表明,DRJ-2S批混批注固壁型冲洗隔离液的冲洗效率达96%以上,较清水提高30%以上,且密度为1.60 g/cm^(3)隔离液的7 d抗压强度为9.6 MPa,可明显提高混合流体抗压强度及水泥环界面胶结强度;90℃、21 MPa下,掺有(4%~6%)DRE-4S的高强度韧性微膨胀水泥浆的抗压强度不小于24 MPa,弹性模量不大于7 GPa,线性膨胀率不小于0.02%,具有较强的力学交变适应性。DRE高强度韧性微膨胀水泥浆体系、DRJ-2S批混批注固壁型冲洗隔离液及配套固井工艺技术在巴彦河套盆地规模应用40多井次,平均固井合格率为96.5%以上,推动了该地区整体固井质量大幅提升,为复杂油气井安全高效开发提供了强有力的技术保障,且具有很好的推广应用价值。
The reservoir formations in the Baran Hetao Basin have the characteristics of low maturity,high permeability,low strength and high shale content.The formations drilled have high water sensibility,instability and leaking potential.Deep well cementing is faced with many difficulties,such as long cementing section,low displacement efficiency,low bonding strengths of the two interfaces and high requirements on the mechanical performance of the cement sheath in late fracturing jobs,etc.To solve these problems,a batch-mixing batch-injecting DRJ-2S flushing spacer and a slight-expansion high strength rough cement slurry DRE have been developed with two key cementing materials,which are an interface strengthening agent DRJ-2S and an expanding toughening agent DRE-4S.Laboratory studies show that the DRJ-2S flushing space has a flushing efficiency of more than 96%,which is 30%higher than that of clean water,and a spacer of density 1.60 g/cm^(3) has 7 d compressive strength of 9.6 MPa.The DRE-2S flushing spacer has the ability of remarkably enhancing the compressive strength of mixed fluids and the bonding strengths of the interfaces of a cement sheath.At 90°C and 21 MPa,a high strength tough slight-expansion cement slurry treated with 4%–6%DRE-4S has compressive strength of at least 24 MPa,elastic modulus of equal to or less than 7 GPa,and linear ratio of expansion of at least 0.02%,indicating that the cement slurry has good adaptability to mechanical alternation.The DRE cement slurry and the DRJ-2S spacer have been used on more than 40 wells in the Bayan Hetao basin,with average well cementing pass rate of 96.5%or higher,greatly improving the quality of well cementing job in the basin.The application of the DRE and the DRJ-2S has provided a powerful technical support for the safe and efficient development of the complex oil and gas wells,and is worth promoting.
作者
闫睿昶
徐明
虞海法
罗玉财
费中明
邱爱民
贾利军
YAN Ruichang;XU Ming;YU Haifa;LUO Yucai;FEI Zhongming;QIU Aimin;JIA Lijun(Bayan Exploartion and Development Branch of PetroChina Huabei Oilfield Company,Bayannur,Inner Mongolia 015000;CNPC Engineering Technology R&D Company Limited,Beijing 102206;First cementing Branch of CNPC Bohai Drilling Engineering Company Limited,Renqiu,Hebei 062550;Bayan petroleum Engineering Branch of CNPC Bohai Drilling Engineering Company Limited,Bayannur,Inner Mongolia 015000)
出处
《钻井液与完井液》
CAS
北大核心
2023年第1期82-88,共7页
Drilling Fluid & Completion Fluid
基金
中国石油天然气股份有限公司课题“华北油田河套盆地钻完井技术研究”(kt2022-5-2)。
关键词
界面增强
高强度
韧性
冲洗隔离液
水泥浆
胶结质量
固井
河套盆地
Interfacial strength enhancement
High strength
Toughness
Flushing spacer
Cement slurry
Bonding quality
Well cementing
Hetao basin
