CAJ | 학술논문

BG-SG特殊螺纹接头是一种针对国内页岩气井专门开发的特殊螺纹接头形式，主要由锥面／锥面主密封结构、直角扭矩台肩结构和双段式螺纹连接部分组成，具有高连接强度、高抗扭等优点，适用于大狗腿度下的复杂井况。基于控制变量法的思想，运用有限元数值仿真计算方法分别研究了密封面过盈量（δ）、密封面长度（l）和密封面锥度（ΔD／L）等三个结构参数对接头密封接触压力分布和密封性能的影响。分析结果表明，δ的增大对接头密封性能有正面影响，但过大的过盈量并不能持续增加有效接触长度，且需控制其值不致引起接头结构的塑性变形或黏结；增加l值，可一定程度上增加密封面的有效接触长度，但超过某个特定长度以后则会在密封面中部产生零接触应力区域；ΔD／L对密封面两侧接触点附近的影响有所不同。根据分析结果优化设计了各结构参数，所开发接头顺利通过实物性能试验，验证了有限元分析的有效性。
BG-SG특수라문접두시일충침대국내혈암기정전문개발적특수라문접두형식，주요유추면／추면주밀봉결구、직각뉴구태견결구화쌍단식라문련접부분조성，구유고련접강도、고항뉴등우점，괄용우대구퇴도하적복잡정황。기우공제변량법적사상，운용유한원수치방진계산방법분별연구료밀봉면과영량（δ）、밀봉면장도（l）화밀봉면추도（ΔD／L）등삼개결구삼수대접두밀봉접촉압력분포화밀봉성능적영향。분석결과표명，δ적증대대접두밀봉성능유정면영향，단과대적과영량병불능지속증가유효접촉장도，차수공제기치불치인기접두결구적소성변형혹점결；증가l치，가일정정도상증가밀봉면적유효접촉장도，단초과모개특정장도이후칙회재밀봉면중부산생령접촉응력구역；ΔD／L대밀봉면량측접촉점부근적영향유소불동。근거분석결과우화설계료각결구삼수，소개발접두순리통과실물성능시험，험증료유한원분석적유효성。
BG-SG is a specifically designed premium connection for domestic shale gas wells drilling.It is composed of three parts of conical/conical seal structure , right angle torque shoulder structure and double-section thread structure , and applies in complex well conditions under big dogleg for having high strength & high torsion-resistance features . Based on control-variant approaches , the finite element method is used to study the effects on sealing contact pressure distribution and sealing performance of the connection structure parameters , such as the seal surface interference (δ) , the seal surface length ( l ) and the seal surface taper (ΔD/L ) .The analysis results show that δhas a positive effect on the sealing performance , however being too large can ’ t continuously contribute to increase the effective contact length , so theδvalue need to controlled at a appropriate amount not to cause plastic deformation or galling .Increasing parameter l can increase the effective contact length to some extent , while the value beyond a certain amount will result in a zero contact pressure zone within the seal surface region .Seal surface taper (ΔD/L) has different influences on either end of the effective contact length .Based on the analysis results , structure parameters of the connection is optimized , and the manufactured connection specimens passed the physical performance test , verified the validity of the finite element analysis .