摘要
普光高酸性气田气井具有高温、高压、高产、超深的特点,流体具有腐蚀性和剧毒性,这些特点要求完井管柱设计既要充分保证安全,又要满足现场施工要求;此外,由于主要采用水平井和大斜度井完井和出现个别井套管严重变形,更加大了设计难度。通过分析普光高酸性气田的投产难点和单井特点,研究确定了完井管柱设计的原则和思路,分井型设计出常规井(永久式)、监测井(永置式)、水平井(层段可选)、套变井(永久式封隔器+遇油膨胀封隔器)等4种不同结构不同特点的永久式酸压、生产一体化完井管柱;选用INCLOY G3镍基合金油管和INC718材质井下工具,采用无固相长效环空保护液配合永久式封隔器的防腐方案,满足了高酸性气井长期安全生产的要求;完井管柱分别采用125钢级φ88.9mm和φ114.3mm油管、VAM TOP气密封扣,整体管柱满足耐压70MPa、耐温150℃、下入深度达6 000m的实际要求。4种完井管柱应用于普光气田的投产实践,设计的可靠性和科学性均得到了验证。
The gas wells in the Puguang Sour Gas Field are characterized by high temperatures,high pressures,high gas yields,and great depths,and fluids inside are highly corrosive and toxic.In such a case,the well completion string will be carefully designed for the safety guarantee and the needs of the field construction.Apart from that,a great challenge is met in such a design because the casing deformation often occurs in some horizontal or highly deviated wells.Therefore,through an analysis of the difficulties in production and the features in a single well in this field,the principles and ideas are determined for the well completion string design.Then 4 kinds of well completion strings with different structures and characteristics are designed adaptable for this sour field,achieving acid fracturing and gas production at the same time:the permanent for regular wells,the implanted for monitoring wells,the layer selectable for horizontal wells,and the permanent packer plus swell packer for casing deformation wells.As for the tubular goods selection,the Ni-based alloy,INCLOY G3,is selected for oil tubings and the material of INC718 for downhole tools;the anticorrosion scheme is chosen by use of the solid-free protection fluid with a long-term effect in combination with the permanent packer,meeting the requirement of steady and safe production in sour gas wells.The Grade Q125 steel oil tubings are chosen with the optimal tubular sizes of 114.3 mm×7.37 mm and 88.9 mm×6.45 mm respectively for the gas wells with the productivity of more than and less than 100×104 m3/d.More than that,with the gas seals VAM TOP designed,the well completion strings can meet the actual requirement of sour gas wells with the depth of 6000 meters under the pressure of 70 MPa and the temperature of 150 ℃.Through application in the Puguang Gas Field,the above 4 designed well completion strings are verified to be reliable and feasible.
出处
《天然气工业》
EI
CAS
CSCD
北大核心
2011年第9期76-78,138-139,共3页
Natural Gas Industry
基金
国家"十一五"科技重大专项"高含硫气藏高效安全开发技术"(编号:2008ZX05017)
