Successful Pinpoint Placement of Multiple Fractures in Highly Deviated Wells in Deepwater Offshore Brazil Fields

摘要

The application of hydrajet technique to stimulate highly- deviated and horizontal wells has become a successful methodto improve well productivity for different field conditions in the world. In the past 2 years, an operator company has successfully implemented a relatively new hydrajet stimulation technique in shallow waters off Brazil. In deepwater locations, additional problems had to be overcome, which proved achievable using this new technology. This paper discusses a reservoir-based methodology to determine the optimum number of transversal fractures for a horizontal deepwater well. The method starts with the review of geology and stratigraphic aspects of the field to better understand the relationship between fracture orientation, geological faults, and regional tectonic effects. With this preliminary characterization, well-log interpretation of the pilot well and horizontal wellbore is performed to identify porosity and permeability index of the carbonate formation being drilled. A study using well testing and nodal analysis is conducted to verify reservoir properties based on real production data. Next, a numerical simulator is used to obtain a production forecast varying the number of transverse fractures intersecting the well. Finally an economic evaluation of net present value vs. number of fractures is performed to determine the optimum number of transversal fractures. Production results are then evaluated and compared to the other stimulation attempts in offshore horizontal completions in the area.