Subsea HIPPS: A Way To Develop High-Pressure Subsea Fields

Abstract

Summary One of the challenges for the development of high-pressure oil and gas prospects in ultradeep water is the high capital-expenditure (CAPEX) cost of subsea flowlines and risers. Installing a high integrity pressure protection system (HIPPS) in the subsea system allows the flowline to be designed to just above well flowing pressure instead of well shut-in pressure. On the basis of flow simulations, pipeline design, and economic analysis, this paper demonstrates that installing subsea HIPPS results in the following: Lower installed cost of flowlines and risers. Early payback with incrementally higher flow of oil and gas. Secondary benefits including higher flowing wellhead and flowline temperatures. Another important benefit of using subsea HIPPS is that the weight of the risers hanging off at the host facility can be reduced substantially. Otherwise, heavy-walled risers may restrict the tie-in of the deepwater prospect to host facilities. With pressure decline over time, the thick-walled flowlines become overkill and tend to restrict the well flow rate. With subsea HIPPS, the larger flow area in the subsea flowlines will allow the field to be abandoned at a lower reservoir pressure. This means that that the total recoverable reserves from the field can be increased. The major finding of this paper is that for high-pressure reservoirs in ultradeep water, installing HIPPS subsea accelerates cash flow and increases the project net present value. These benefits will be illustrated on the basis of the analysis of a deepwater field-development design case.