Due to the complication and variety in the hole especially the time that is needed to transmit pressure it is very inconvenient to use choke valve to control standpipepressure.
但井下情况复杂多变,尤其是压力传递需要时间,给调节节流阀控制立压带来不便。
2
Drilling parameters typically include flow rate, pump pressure, standpipepressure (SPP), pipe rotation (RPM), weight on bit (WOB), rate of penetration (ROP) and pit volume (PVT).
流量、泵压、钻压以及机械钻速等常用钻井参数还可用于监测井涌和泥浆漏失。
3
The negative pressure gradient and slip velocity in standpipe increase with the increase of circulating rate.