Research On Dynamic Annular Pressure Control Application Technology

Managed pressure drilling is an advanced technique applying in abroad. The most major characteristic of this technology is that it can precisely manage wellbore pressure through back pressure. It is particularly applicable for reducing the risk of loss, kick and stuck when drilling in a complex formation. This article discusses the disadvantages of managed pressure drilling, and gives a solution that is dynamic annular pressure control drilling (DAPC). DAPC is a new pressure control drilling technology that is mainly aims at depleted reservoir, narrow window reservoir, abnormal pressure reservoir and so on. DAPC can precisely manage wellbore pressure while drilling, making a connection and well kick occurrence.This paper introduces equipment, the characteristics of various types of equipment as well as the relationship of DAPC, gives hydraulics model of DAPC and proposes amendment method of hydraulics model by PWD data. DAPC uses PWD data to amend real-time data, and precisely manages wellbore pressure through back pressure. When making a connection, wellhead back pressure is caused by pumping drilling mud in annular through automated pump. Observed kick by coriolis flow measurement, DAPC manages wellbore pressure through back pressure and circulates out the gas which is produced in kick safely. This article gives structure diagram of control wellbore pressure through high speed pressure controller, produces methods and the hydraulic model when PWD data is error.