Maximizing the Value of Reservoir Fluid Samples for Surveillance and Production Monitoring Applications
Russell Kaufman and Rong Hwang
Chevron Energy Technology Co., San Ramon, CA
Today there is an increasing array of sophisticated technologies available for imaging the subsurface, modeling reservoir performance and monitoring oil and gas production. Yet there remains a basic need to thoroughly sample and analyze the reservoir fluids that either will be or are being produced. To gain the maximum value from these analyses, reservoir fluid sampling programs need to be well designed and integrated into well testing and reservoir surveillance programs, not developed after the fact. Successful implementation of these applications requires the proper collection and storage of fluid samples through out the field development history.
Historically, the application of geochemical methods in reservoir surveillance has been fairly limited. Many of these have involved monitoring producing wells to either allocate commingled production to individual reservoirs or identify behind tubing string and casing leaks. Other applications exist, however, which utilize compositional variations with the reservoir. Examples include monitoring compositional changes with time associated with the updip movement of the oil-water contact, identification of swept and un-swept zones during waterflooding based on the extent of water washing, and monitoring flood front movements in EOR processes based on compositional differences between the injected and produced fluids.
This paper will present examples and case histories of how geochemical methods have been used in reservoir surveillance programs. New methods of analysis and an improved understanding of how reservoirs fill and mix over time provide additional opportunities for future surveillance applications.
AAPG International Conference and Exhibition, Cape Town, South Africa 2008 © AAPG Search and Discovery