Research On Rapid Monitoring And Control Technology Of Normal Drilling Fluid Intrusion In Controlled Pressure Drilling

Managed Pressure Drilling(MPD)is a drilling technique for precisely controlling the entire wellbore annulus pressure.However,it can not completely prevent the formation fluid invading into the wellbore.In the process of the normal drilling,if the technical staff don't find the formation fluid invade into the wellbore and take no appropriate action,it will lead to serious consequences.Therefore,to seek a method that aiming at MPD technology with timely,accurately and rapidly fluid invasion monitoring,and forming the respective control technology after the fluid invasion has important practical significance.This paper investigated a wide range of domestic and foreign fluid invasion detection methods,and researched deeply at the fluid invasion detection methods and the models,the specific research contents are as follows:1.This paper researched the mechanism of fluid invasion,summarized the characteristics and laws of fluid invasion;compared and analyzed the advantages and disadvantages of various fluid invasion detection methods,Preferred the fluid invasion detection methods based on standpipe pressure and casing pressure.2.This paper researched the pattern recognition,Preferred fluid invasion detection model based on the Bayesian classification method,made simulation of the classifier model,eatablished the fluid invasion intelligent monitoring model eventually.Designed and developed the collecting system and the monitoring system for the model which was established,and completed the matching hardwares.3.On the basis of in-depth study of MPD wellbore flow,researched the MPD safety drill and control technology,simulated and analyzed how the control parameters influenced the parameters of annulus.4.Tested the field applicatin,analyzed field application effect of the system.