海上热采井完井封隔器卡瓦结构优化

Structure optimization of completion packer slips for offshore thermal recovery wells

梁月松 季正欣 李良庆 陈学江 张清龙

LIANG Yuesong JI Zhengxin LI Liangqing CHEN Xuejiang ZHANG Qinglong

中海油田服务股份有限公司油田生产事业部

Oilfield Production Department, China Oilfield Services Ltd., Tianjin 300459, China

为满足热采工艺要求，渤海油田稠油开发井普遍采用高钢级生产套管，现场作业中常出现完井封隔器坐封之后因悬挂力不足而定位失败的问题。为此，结合封隔器分瓣式楔形卡瓦结构特点，以卡瓦牙齿面与套管内壁全接触为设计依据，优化设计新型封隔器卡瓦，通过受力分析推导得出封隔器卡瓦咬入套管深度的理论计算模型，结合卡瓦咬入套管深度和卡瓦牙结构，得出新型封隔器卡瓦剪切强度的计算模型。通过理论计算和有限元法对设计卡瓦进行了优化分析，对比分析了卡瓦外径、坐封力和套管钢级对卡瓦悬挂极限载荷的影响。计算分析表明，卡瓦外径是影响卡瓦悬挂力的主要因素，非同心全接触楔形卡瓦可以大幅提升卡瓦悬挂能力。室内测试表明，在坐封力350 kN情况下，新型封隔器卡瓦能够有效锚定TP125H钢级套管，满足现场工况要求，有望解决现场技术难题。

In Bohai oilfield, the production casing of high steel grades is commonly used in wells of heavy oil recovery to meet the technical requirements of thermal recovery. However, positioning failure of completion packers after setting often occurs in practice, due to insufficient suspension force. Given this, a novel packer slip was developed via the structural optimization in accordance with the structural features of the split wedge slip of the packer and the design requirement for full contact between the slip tooth face and inside wall surface of the casing. A theoretical model was developed via the force analysis to calculate the penetration depth of the packer slip into casing, and moreover, the calculation model of the shear strength of the presented packer slip was constructed with respect to the penetration depth of slip teeth and slip structure. The slip design was optimized via both the theoretical analysis and finite element method, and the effects of the slip outside diameter, setting force and casing steel grade on the limit suspension load of the slip were investigated. The calculation showed that the slip outside diameter is the major factor affecting the slip suspension capacity, and the eccentric full-contact wedge slip greatly improves the suspension capacity. Laboratory testing demonstrated that the presented packer slip can effectively anchor casing of the TP 125H steel grade, with a setting force of 350 kN, which meets the operation requirements. The presented packer slip is promising for solving field technical difficulties.

10.13639/j.odpt.202303038