肯基亚克盐下油田小井眼取心技术

哈萨克斯坦肯基亚克盐下油田油层埋藏深，地质条件复杂，特别是更改为四层井身结构后，?149.2 mm小井眼高密度钻井液钻进，更增加了勘探开发难度，也给该地区钻井取心作业造成了极大困难。为克服肯基亚克盐下油田地质条件复杂、钻井液密度高等技术难题，通过分析盐下油藏地层规律，结合该区块钻井技术特点，研制了小直径高强度取心工具。通过采用带扶正机构的铝合金内筒和密封轴承提高了内筒稳定性，通过采用新型取心钻头，增加篮式岩心爪和防钻井液倒返装置，提高了取心作业效率和取心收获率。现场应用表明，该技术能够有效克服该区块钻井取心技术难题，取心效果提升明显，值得进一步推广应用。

Slim hole coring technology in Kenkyak sub-salt oilfield

The Kenkyak sub-salt oilfield in Kazakhstan is characterized by deep buried depth of oil reservoirs and complex geological conditions.And especially in the fourth casing section (?149.2 mm), high-density drilling fluid is used.As a result, the exploration and development difficulty is increased and great challenge is bought to the coring operation in this block.In order to overcome the difficulties of complex geological conditions and high-density drilling fluid, the stratigraphic laws of sub-salt oil reservoirs were analyzed, and then based on the characteristics of the drilling technologies applied in this block, a high-strength, small-diameter coring tool was developed.In this coring tool, the stability of inner barrel is improved by using the sealed bearing and the aluminum inner barrel with centralizer, and the coring operation efficiency and the core recovery are increased by using the new type coring bit, the basket type core catcher and the flapper float valve.Field application results indicate that by virtue of this new coring technology, the drilling and coring technical difficulties in this block are solved and the coring results are improved remarkably.Obviously, this technology is worth popularizing and applying further.