东胜气田刘家沟组井漏与堵漏措施分析

Analysis on Plugging Measures for Leakage in Liujiagou Formation of Dongsheng Gas Field

摘要:

自2013年东胜气田步入开发以来，随着水平井逐渐增多而井漏事故频发，单井堵漏时间大体占钻井周期的8%～50%，极大地制约了提速提效。主要漏层为刘家沟组，钻井液密度低时发生渗透性漏失，漏速约为3～5 m3/h，当钻井液密度高时，发生裂缝性漏失，漏速20 m3/h直至井口失返。裂缝会随井内液柱压力的增加而扩大延伸，极易造成井漏的反复。刘家沟组恶性漏失严重制约了该工区钻井的提速提效。通过对J58P13H井井漏特点与堵漏效果分析，探索复合堵漏法、大裂隙膨胀堵漏材料和膨胀管堵漏法等在裂缝性漏失堵漏中的适应性，以便在东胜气田试验推广。

Abstract:

Dongsheng gas field stepped into the development period in 2013. Along with gradual increase of horizontal well construction, lost circulation accidents occur frequently, single well plugging time in drilling cycle was roughly 8%～50%, which greatly restricted the drilling efficiency. The main leakage zone was in Liujiagou formation, the permeability loss happened when drilling fluid density was low with 3～5m3/h leakage velocity and crack leakage occurred when drilling fluid density was high with 20m3/h leakage velocity until annular return lost. The cracks would expand with the increase of the borehole liquid column pressure, which would cause repeated lost circulation. By the analysis on the leakage characteristics in J58P13H and plugging effect, the adaptability of the composite plugging method, plugging materials for large crack expansion and expansion pipe plugging method in fractured leakage plugging were explored in order to promote these methods in Dongsheng gas field.