A method for planning well control operations involving an induced fracture
- Petrobras, Rio de Janeiro (Brazil)
- Louisiana State Univ., Baton Rouge, LA (United States). Dept. of Petroleum Engineering
Although many ways (the use of barite plugs, cementing, packers, etc.) to control underground blowouts exist, this paper will focus on the dynamic kill method as a mean to regain the control of the well. The dynamic kill method is a well control procedure that calls for pumping down the drill pipe with a flow rate that causes the bottom hole pressure to exceed the formation pressure, thus displacing the fluids out of the annulus. The process consists of varying the mud flow rate, and calculating for each flow rate the hydrostatic pressure and the losses occurring in the annulus of the well. The bottom hole pressure is then calculated by adding the hydrostatic pressure and the pressure losses to the fracture initiation pressure which is considered constant. This process is unrealistic because the fracture initiation pressure will change with time as the fracture propagates and as the flow rate is increased. The main objective of this study is to evaluate when the assumption of a constant fracture injection pressure will lead to unacceptable errors in the design of a dynamic kill procedure. The evaluation is accomplished using a new computer model that couples a hydraulic fracture model with conventional reservoir and wellbore models using a system analysis approach. The program can predict fracture dimensions and fracture pressure in any cross section of the fracture as well as pressure in any part of the wellbore. The program emphasizes the bottom hole pressure, pressure in front of the fracture and producing gas during the underground blowout.
- OSTI ID:
- 287841
- Report Number(s):
- CONF-960154--; ISBN 0-9648731-8-4
- Country of Publication:
- United States
- Language:
- English
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