薄油层多底井井眼轨迹中调整点的确定及应用

大庆油田州扶90-46区块多底井Z72-P54Z井的第四分支段最薄油层平均厚度地质预测只有1.0 m，给多底井钻井设计与施工带来很大的难度。找出薄油层中分支段最优调整点对于提高油层钻遇率及钻完井管柱安全下入至关重要。通过优化多目标数学模型确定了调整点的三维坐标，结合单圆弧模型即可得出既能满足施工要求又能保证钻遇率的最优井眼轨迹，可以最大限度地穿过薄油层靶区，又能减少主井眼下管柱时误入分支井眼的风险。通过现场验证该轨迹适合现场施工，保证了大庆油田多底水平井的顺利完钻，完成了分支段在厚度1.6 m的薄油层内成功钻进，形成了一套适合大庆油田的分支井钻井优化设计技术。

Set-point determine and application for multi-bore well in thin oil layers

The fourth branch of the multi-bore well Z72-P54Z is in a thin oil layer with average thickness of only 1 m in Zhoufu 90-43 block, DaQing Oilfield, which brings difficulty for multi-bore well drilling design and construction. Based on well track design software, the design model is optimized, which can ensure the utmost passing in the thin oil layer target zone, and can ensure the branch is upside the original hole, so it can decrease the risk of entering the branch hole while running string into original hole. Two multi-bore wells were drilled successfully in DaQing Oilfield, and the branch hole was drilled successfully in the thin oil layer with 1.6 m thickness. It forms a special technology which suits branch hole drilling optimization design in Daqing Oilfield, and it is precedent in China at present.