Sir Ian’s Wood Report, published last year, identified technology as an integral component to ensuring the success of maximizing the economic recovery of the UK Continental Shelf (MER UK).
As the Wood Report states, new field discoveries in the North Sea tend to be of a diminishing size and in more challenging environments, including deep water. Technology needs to safely deliver cost reductions to enable new field developments in these marginal fields and improve competitiveness on existing assets, helping secure the long-term future of the UK oil and gas industry.
Deepwater drilling and reservoirs, like those found West of Shetland, pose unique challenges. The UKCS can leverage and benefit from technologies developed for deep water environments, such as the Gulf of Mexico, where subsea separation, subsea compression and subsea samplings are opening up new opportunities and enabling further development of existing deepwater fields.
Fields, which were previously considered stranded have also, benefited from technology advancement, with increases to the maximum tie-back distances from under 50km in the 1990’s to over 100km today. This capability has been an enabler for the development of these marginal fields and means that costly, new and dedicated facilities are no longer required.
While capitalizing on innovative technologies to develop marginal fields will play a key role in achieving MER UK, there is also a need to improve the recovery of resources from mature fields. A technology that has the potential to increase resource capture is enhanced oil recovery (EOR). EOR techniques increase the recovery of oil from reservoirs compared to more conventional recovery methods, such as water flooding, and can benefit both existing and new fields.
At the Captain field, we have a proven track record of deploying innovative technologies, like extended reach drilling and novel artificial lift systems to access new areas and increase resource capture. Building upon this, we recently completed pilot trials of polymer EOR. The field was developed using proven technology in horizontal infill well development and the standard industry practice of water flooding. At this stage of the field development water injection alone is inefficient due to the high viscosity of the crude. This is the fundamental principle behind polymer flooding; low viscosity water is not very effective at pushing high viscosity oil out of the reservoir and into the production wells. Adding polymer to the injection water increases its viscosity and has the potential to improve the recovery of the relatively heavy Captain crude.
The use of polymer injection is a proven EOR system and is an established practice in onshore fields globally. Over the past five years, we have safely carried out polymer injection trials in the offshore Captain field. The successful outcome of these trials has demonstrated that polymer flooding is technically feasible in this field and has helped shape plans for full-field polymer injection deployment.
A key economic enabler for the pilot was the foresight shown by the field development decision to include some polymer handling capacity in the original facilities design for Captain. This illustrates the importance of giving serious consideration to the full life-cycle of the field when field development concepts are being analysed, ensuring that EOR and late-life capability is assessed and factored into the design as appropriate.
In December 2014, the full field polymer deployment successfully moved into front end engineering and design (FEED) and contracts were awarded to two UK companies. This represented a positive step towards commercialising Captain EOR and underlines our confidence in the expertise of the UK supply chain.
Detailed analysis is currently being conducted to further refine the chosen concept, which includes the installation of a new bridge linked platform (BLP-B) that will house the polymer storage, mixing and pumping facilities. Modifications to existing infrastructure to tie in the new facilities are also in scope, alongside drilling and completion of new polymer injections wells.
Technology has improved the recovery of resources and opened up fields which are challenged from either a cost or technical perspective by making the impossible, possible. We need to continue to push the technology boundaries, to solve the challenges ahead and achieve the vision of MER UK.
Background
The Chevron-operated Captain field is located offshore approximately 68 mi north of Aberdeen. In 2013, net daily production at the Captain field, a joint venture between Chevron (85% interest) and Dana Petroleum (E&P) Ltd (15% interest), averaged 25,000 barrels of liquids and 3 MMcf of natural gas.
Craig May currently serves as managing director of Chevron upstream Europe’s (CUE) strategic business unit. Headquartered in Aberdeen, Scotland, CUE manages exploration and production in the UK, Norway, Denmark and Greenland.
Craig earned a bachelor of science degree in Civil Engineering from Mississippi State University and a master’s degree in civil engineering from Tulane University. He began his career with Chevron in 1981.
Prior to joining CUE, Craig was Chevron Energy Technology Co.’s general manager for the facilities engineering department, which serves as a center of expertise for engineering disciplines including mechanical, subsea and pipeline, civil structural, process automation and reliability and integrity. Over his career, Craig has also held a variety of positions in construction, facilities, project and technology management in the USA, UK, and Australia.
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