underbalance

1.While underbalance drilling spreads greatly, rotating blowout preventer, as a kind of high technical product, is the crucial equipment to control well pressure.

国内欠平衡钻井普遍实施,要用到旋转防喷键设备,技术含量高。

2.The minimum underbalance is independent of viscosity and compressibility and of reservoir fluids.It is a function of the formation porosity, permeability and radius of perforation channels.

最小测试压差不依赖于地层流粘度和压缩性，而为地层孔隙度、渗透率和射孔孔眼函数。