Expro Group says lightweight, mobile systems are needed to meet future deepwater intervention needs. Demand for deepwater subsea well intervention services continues to grow. However, to date, the focus remains on completions for new field developments.
As subsea field age and production rates begin to decline, operators are looking towards subsea intervention to maximize reserves across the field.
The technical challenges of deepwater intervention are well documented in the industry, including the need for costly rigs or vessels to undertake this work. Expro has forecast the demand for deepwater intervention across several of its major business regions over the next five years, including the Gulf of Mexico, West Africa and Brazil.
Image: A riser control module (RCM), a component which makes up the full subsea landing string. Photo: Expro Group.
We anticipate high market demand for lightweight portable systems, which will support deepwater fields with increasingly complex issues—as opposed to oneoff solutions.
There is now a critical mass of maturing subsea wells and architecture in place, therefore there will be an increasing demand for well intervention services. It is important that we look towards planned intervention, assessing operator’s demands, current technology in place, limitations and how we can develop a solution to address these combined needs. Indeed oil and gas operator’s demands may change with marketdevelopments, not only in terms of equipment that can be utilized from smaller vessels, but a move towards emphasis on the full life cycle of a field.
Both operators and service companies have a need for streamlined technology, as neither want to be driven into deploying expensive large rigs or vessels. Lighter weight and flexible systems that could be pre-loaded on to vessels, to provide a multifunction system, are much more desirable—and economically viable.
At present, the market is served by two conveyancing methods. These are wire in water, where wireline is deployed from a dedicated vessel via a subsea lubricator, and riser-based systems, capable of operating in deepwater and able to run coiled tubing.
The riser-based systems on the market are mostly provided by Christmas tree vendor companies and run by operators. Intervention systems are sold as part of the overall subsea tree package, which can be used to run the trees and clean up wells. However, this isn’t fully utilized until intervention is required. This can create issues in terms of maintenance and integrity of the equipment at the point of use.
Operators are still looking for a “one-stop shop” that can intervene in a well, provide a full conveyancing system, subsea and surface hardware, and riser services. Working directly with operators, Expro has set up a project team that has started work on conceptual studies for a new system, to adapt existing field-proven technology, currently used in completion, and which could be mobilized on different vessels.
This lightweight riser-based system, capable of deepwater operations, is being designed for use on Category B mid-size rigs or vessels, with a view to being mobilized and demobilized quickly.
The design of the intervention system will be based on the latest subsea landing string as, fundamentally, both systems perform the same function. The only difference is that a landing string is deployed within a blowout preventer and marine riser, which isn’t exposed to the same global loads as an open water intervention system. In parallel, Expro is also developing designs for a new landing string compliant with API 17G, including cut and seal capability and high-angle disconnect, which is due to reach the market in 2014-15.
Expro has drawn on its experience developing the AX-S system, which was aimed at the lightweight intervention market, but still relied on large vessel mobilization.
Significant investment is needed to develop technology. It is essential that the industry works together and moves forward on a partnership basis to ensure alignment. Operators need assurances that solutions can be provided that will fill demand and service companies need commitment that technology once developed will be deployed.
However operator feedback is consistent — the need to advance subsea well intervention technology exists and will increase. A “technology transfer” approach is the route forward to encourage the evolution of existing technology and modify this to apply to the challenges of deepwater intervention. OE Review
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