Smart completions that can remotely control the flow from multiple layers of a reservoir interval were introduced in the mid 1990's. Downhole flow-control (DHFC), as it has become known, has since been installed in hundreds of wells. However, there has been very little use of these valves to control water injection distribution within the layers of a reservoir interval at high rates (>25,000 BWPD) in a continuous proportional operating mode. This paper will review BP's efforts to team with manufacturers to deliver new technologies that can reliably provide this functionality.
By 2010 a significant portion of BP's production will come from complex water flooded reservoirs, in an environment of rising operating costs. The injection wells in these fields need to accept, in some cases, up to 65,000 barrels water per day. The use of DHFC reduces the number of injection wells by using one wellbore to enable conformed injection into multiple intervals. This eliminates the need for injection wells dedicated to a specific layer to achieve injection conformance.
BP has been progressing the development of DHFC systems for water injection wells since 2001 through collaboration with technology developers. Assurance related activities are an important aspect of these technology developments. This paper will describe several assurance activities and the scope of work involved in each, including:
Development of a Basis of Design
Development of a Statement of Requirements
FMECA (Failure Mode Effects and Criticality Analysis) at component and system levels
Detailed Design Review
Base performance qualification testing
Full scale HALT (Highly Accelerated Lifetime Testing) of critical features
Stack-up and system integration tests
Establishment of Global Quality Control Plans for manufacturing
A case study will be presented, describing the application of the above processes to a choking downhole flow control system being deployed by several BP Projects.
BP's portfolio of future opportunities is characterized by complex layered reservoirs hundreds of feet thick that require water flood for optimum recovery. In many cases, the injectivity contrast between the major layer elements is such that attempts to utilize a single injection well to flood all layers would result in poor sweep efficiency.
Traditional solutions to this situation include:
Completion of a separate injection well to each major layer
Completion in one layer of the reservoir at a time, with subsequent intervention recompletions.
Commingled injection into multiple layers with a later intervention to attempt to correct the injection profile.