Seismic Permanent Reservoir Monitoring PRM - Multi-Disciplinary Integration and Communication Required

摘要

Offshore Seismic Permanent Reservoir Monitoring (commonly known as PRM) is a seabed-basedrntechnology that is becoming part of the reservoir engineer’s toolkit in practicing better management of oilrnand gas fields. In its most commonly practiced form, PRM involves conducting 3D seismic surveys atrnrepeatable time periods, generally somewhere between six months and two years. The time intervalrnbetween surveys may be variable, and depends on the specifics of the reservoir being monitored. It hasrnbeen demonstrated to be a technical success because, as fluids are injected and/or produced from a field,rnthe seismic data change in response to the changes in the reservoir. The field implementation of PRM hasrnnow become a major geoscience and engineering activity yielding tangible results.rnThis paper is an attempt to present an overview, facts, and opinions that will be of use to engineers andrngeoscientists who are interested in what has been done, and what may be done, in the use of seismicrnpermanent reservoir monitoring, or oilfield surveillance. The PRM market appears to be on an upswing,rnbut it remains to be seen if that upswing continues.rnThere are several reasons that have tempered the adoption of this technology. Two are beingrnemphasized here. One is that it has been difficult to determine and publicize the cost-effectiveness ofrnPRM. While upfront costs are relatively large compared to many geological and geophysical activities,rnthey are not large when compared to overall field development, optimization, and maintenance costs.rnCompanies are now taking a more realistic look at the ultimate value derived from PRM due to therngrowing number of published benefits versus cost.rnThe second moderating reason emphasized here is the number of stakeholders, with a wide variety ofrntechnical expertise, perspectives, objectives, and motivations, which must be involved in approving andrnexecuting such a project. This situation is being addressed as more corporate leaders are made aware ofrnhow PRM may address, in addition to production and operational needs, a number of health, safety, andrnenvironmental (HSE) concerns, broadening the interested constituent base within operating companies,rnand further establishing the benefits, both technical and economic, of PRM.rnThere are currently 13 installed PRM projects, with the longest-running (Valhall) having beenrnoperating since 2003. The high-quality seismic data obtained from these projects are capable of showingrnvery small changes in seismic amplitude and/or travel time that result from changes in the reservoir andrnits contents, such as fluid type, saturation, and pressure. The seismic systems themselves have also become the vehicle to integrate other measurements at the seafloor, such as temperature, water chemistry,rnor small changes in seafloor topography – all parameters that may have HSE implications. The growingrnimportance of this oilfield surveillance approach will ultimately result in a variety of engineers collaboratingrnnot only with geoscientists, but also with other departments within the corporation such as Qualityrnand HSE. As shown by the technical and economic successes of at least two projects (Valhall and BC10),rnthe appropriate use of a PRM system significantly increases recovery, production rates, and operationalrnefficiency, and reduces reservoir management costs (Chen and others, 2015, Barkved, 2012, Caldwell,rn2009, Caldwell and others, 2015).