## LSU Historical Dissertations and Theses

1997

Dissertation

#### Degree Name

Doctor of Philosophy (PhD)

William R. Holden

#### Abstract

An advanced prototype computer-assisted deep water drilling well control system was developed using process control technology. The goal of the system was to improve rig safety by reducing the potential for surface and underground blowouts through providing enhanced bottom hole and casing seat pressure control during the well kill process. The system developed is capable of full computer control of the fluid pump and drilling choke control functions during normal well control operations. The system provides computer-assistance in collecting and curve fitting slow circulation rate pump pressure data, in developing a well kill program (kill sheet), and in detecting anomalies such as underground flow, underground blowouts, washed out chokes, etc., with the use of rule based knowledge during the well kill procedure. In addition to providing the process control functions during well control events, the system can provide the monitoring function during normal drilling and circulation. Testing and validation of the system was completed at Louisiana State University's Petroleum Engineering Research and Technology Transfer Laboratory with the use of two subsurface configured wellbores. A 6000 foot true vertical depth (TVD) subsurface configured well emulating 3000 feet of water depth and 3000 feet of solids penetration and a 3000 foot TVD subsurface configured well emulating 1000 feet of water and 2000 feet of solids were utilized in testing the prototype. A total of 50 salt water and 35 natural gas kick experiments were completed during the development and testing phases of this work. The results obtained indicated that bottom hole pressures can be controlled to within $\pm$20 psi as compared to $\pm$200 psi commonly demonstrated with experienced field personnel when using the same well facility and controlling the fluid pump and drilling choke manually as is the current field technology. All programming was completed using the BASIC computer language in conjunction with use of the LabView$\sp\circler$ programming system developed by National Instruments, Incorporated.

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