欠平衡泡沫钻井气液排量优化设计

Optimum gas and liquid injected rate during unbalanced foam drilling

陈勋¹ 闫铁¹ 毕雪亮¹ 逯广东¹ 秦艳宇² 杜婕妤³

东北石油大学石油工程学院，黑龙江 大庆 163318 中国石油大庆油田有限责任公司采油二厂，黑龙江 大庆 163453 中国石油华北油田分公司采油四厂，河北 任丘 062552

College of Petroleum Engineering, Northeast Petroleum University, Daqing 163318, China No.2 Oil Production Plant, Daqing Oilfield Co. Ltd., PetroChina, Daqing 163453, China No.4 Oil Production Plant, Huabei Oilfield Company, PetroChina, Renqiu 062552, China

与常规钻井液不同，泡沫流体具有可压缩性，而且需施加一定回压将泡沫特征值控制在一定范围内，以保持泡沫稳定性。常规钻井液的水力参数优化模型不能直接应用于泡沫钻井的排量优化设计，因此，从泡沫钻井压力分析入手，基于最大钻头水功率工作方式，考虑了泡沫的压缩性和泡沫特征值，建立了泡沫钻井的排量优化计算模型。最后应用建立的排量优化模型，进行了一口井的气液排量设计计算。由于模型中的压力计算避免了复杂的数值求解，因此计算速度快，适合现场应用。

Unlike conventional drilling fluid, foam fluid is compressible. In order to maintain the foam stability, a certain backpressure has to be applied to ensure that foam quality at the surface does not exceed a certain limit. The classic hydraulic-optimization theory developed for incompressible drilling fluids can not be directly applied to hydraulic optimization of foam drilling because of the compressible nature of the foam. Considering foam drilling pressure, maximum bit-hydraulic-horsepower criteria and foam compressibility and stability, optimum foam-flow rate model is built. The model is applied to a well calculation. Without complex numerical solution, the pressure calculation of this model is fast and is suitable for field application.

10.6056/dkyqt201506030