微小井眼水平伸长影响因素研究

Investigation of Factors Affecting Microhole's Horizontal Displacement

微小井眼钻井技术是近10年提出的一项低成本勘探开发浅层油气藏的技术。微小井眼钻井技术与水平井技术结合,在薄油藏、稠油藏、边际油藏、枯竭油藏等领域具有明显的优势。由于工艺技术及装备水平限制,微小水平井眼水平延伸能力受到多种因素的制约。分析了地面装备性能、井壁稳定因素、摩阻及产能等因素对微小井眼水平伸长的影响。结果表明,水平段伸长极限随着钻井泵额定泵压、地层破裂压力及连续油管抗弯刚度的增加而增大,而经济性产能表明水平段存在最优长度。其中,连续油管与井壁的摩阻对微小井眼水平伸长的限制较大。各影响因素决定的微小井眼最大允许水平伸长值中的最小值即为微小井眼水平段的设计长度。

Microhole drilling technology,a newly developed technology over the past decade,is a low-cost exploration and development technology which mainly applied to shallow reservoir.Combined with horizontal well technology,microhole drilling technology has obvious advantages in thin,heavy oil,margin and depleted reservoirs.The maximum horizontal extension of microhole well is limited by several factors.The effects of the factors on microhole well horizontal extension were analyzed,including equipment performance,wellbore stability,formation factors,and friction and production capacity.The results showed that microhole horizontal extension increases with rated pump pressure,formation breakdown pressure and bending rigidity of CT.While economical production shows that there is an optimal value in horizontal extension.The friction between CT and wellbore has more impacts compared with others factors.The minimal of maximal horizontal extension determined by above factors is the optimal designed length.