基于测井资料确定迪那构造的漏层位置

"井漏"是指钻井作业过程中,钻井液漏入地层的一种井下复杂现象。它不仅会耗费钻井时间、损失泥浆、使钻探成本上升,而且还可能导致卡钻、井喷、井塌等井下一系列复杂情况,造成地层伤害。为了有效地实施堵漏作业,必须明确漏失井段的位置、漏失深度和漏失性质。迪那构造上第三系到白垩系砂泥岩地层存在异常高压、压力系数高达2.2,钻井液密度高、窗口窄造成井漏频繁、严重。根据钻井液漏失现象在测井资料上的响应特征,提出了通过常规测井资料结合成像测井资料寻找漏失层段和分析漏失性质的综合评价方法。将该方法用于分析迪那构造的6口井所确定的准确合理的漏层位置、井漏情况,效果明显,为钻井堵漏作业提供了直观可靠的依据。

CONFIRMING THE POSITION OF WELL LEAK IN DINA STRUCTURE BASED ON LOGGING DATA

Well leak is a complex instance of drilling fluid seeping into stratum during drilling operation. It does not only take drilling time, lose mud and increase drilling cost, but also lead to a series of complicated situation which will create stratum damage such as stuck, blowout and borehole collapse, etc. In order to implement leak stoppage effectively, the position, depth and property of the leaky interval must be definite. There is abnormal high pressure from the a-hove third system to the chalk system in Dina structure, which pressure coefficient is as high as 2. 2. The drilling mud density is high and the window is narrow, which cause frequent and severe well leak in Dina. According to the response characteristics of the drilling mud leak on logging curves, an integrated evaluation procedure is put forward that looking for leaky intervals can be carried out through conventional logging data combined with imaging logging data. The method was used to analyze 6 wells in Dina structure to confirm the position and situation of leaky interval. It gained good effect and provided visual and reliable gists to the drilling leak stoppage operation.