Technology scaled for any response

Dedicated well control services were established in the deepwater industry, just over a decade ago. In that time, technologies have advanced rapidly. From delivery of the first subsea capping stack in 2010 to the completion of the first high-pressure, high-temperature (HPHT) containment system in 2020 (Fig. 1.), the industry, led by Marine Well Containment Company (MWCC), has innovated to keep pace with drillers in the region.

Fig. 1. MWCC completed the industry’s first high-pressure, high-temperature (HPHT) containment system in 2020.

ADAPTING TO DEEPER WATER

Born out of necessity following the 2010 Deepwater Horizon incident, MWCC delivered on mandates set forth in Notices to Lessees and Operators (NTL), issued by the Department of Interior’s Minerals Management Service, subsequently renamed the Bureau of Energy Management (BOEM), related to new emergency response capabilities required for operators to drill in the U.S. Gulf of Mexico. These requirements, commonly referred to as the Well Control Rule, were later codified into federal regulation 30-CFR-250, finalized and issued in 2019 by the Bureau of Safety and Environmental Enforcement (BSEE).

In 2010, deepwater drilling fell comfortably within the existing technical standards established for pressures up to 15,000 psi and temperatures of 350°F. Early well control equipment met these demands with traditional blowout prevention and subsea production technologies.

Over time, drillers in the U.S. Gulf of Mexico moved into deeper water and drilled increasingly deeper wells. Since 2015, MWCC’s members have drilled over half of their wells in water depths greater than 5,000 ft. Many of them reach depths of 15,000 ft. or more below the seafloor, where, according to BOEM, more than half of remaining U.S. offshore oil and gas reserves reside.

HPHT REGULATION

Deeper wells often equate to higher pressures and temperatures, and by 2012, it was apparent that traditional technologies would be insufficient in future incident responses. The modern definition for HPHT was set by the American Petroleum Institute (API) in its 2012 Technical Report, 1PER15K-1 Protocol for Verification and Validation of High-Pressure High-Temperature Equipment, which classifies any well that exceeds either 15,000 psi, or 350°F, as HPHT. The deepest wells may simultaneously exceed both the pressure and temperature thresholds.

Containment technology designed for use in conventional wells was ram-based, and included soft goods in the sealing and pressure-containing components. While this approach proved effective, difficulty in developing soft goods for HPHT applications drove a change of course in the conceptual design of HPHT containment equipment.

CAPPING STACK DEVELOPMENT

Shell was the first to engineer a capping stack for HPHT well control. The company began developing the world’s first high-temperature, 15k/400°F capping stack (Table 1) in 2013, for application at its Appomattox field, working with Trendsetter Engineering to deliver the technology in 2017. Together, they shifted the traditional construction of a capping stack from ram-based to valve-based. Engineering studies demonstrated that valve-based containment assemblies are more effective for HPHT applications. The valve-based designs eliminate use of soft goods, instead relying upon much-harder metal gaskets and seals.

MWCC has maintained the 15K/400°F capping stack since its 2017 delivery, and has held accountability for deployment and installation on behalf of Shell. Maintenance of a valve-based capping stack is more efficient, and components have proven to be very robust and reliable. The use of valves reduces bulk and weight, making capping stacks easier to deploy in the event of a well control incident.

FURTHER HPHT WORK

By 2015, MWCC recognized that additional HPHT well control capabilities were needed to meet upcoming drilling demands. MWCC’s team of dedicated engineers partnered with two of its member companies—Chevron with its expertise in high-pressure applications, and Shell with its expertise in high-temperature applications—to begin designing the HPHT equipment that MWCC needed to cover future wells. Additional front-end technical support was provided by MWCC’s Technical Committee, comprised of representatives from all member companies. Tapping into the vast technical capabilities of member companies has been a critical enabler to MWCC’s strategic advantage of remaining at the leading edge of industry advancements.

In 2015, MWCC selected Trendsetter Engineering, the world’s leading developer of subsea containment technology, kicking off the engineering, procurement and construction (EPC) process for the world’s first high-pressure (20K/350°F) capping stack. The original design on the 20K had five outlets and a projected weight of 325,000 pounds. Through various design optimizations, MWCC removed one outlet and reduced the final dry deployment weight to 256,000 pounds, enabling deployment using offshore construction vessels (OCVs) with 250-MT heave-compensated cranes that are commonly available in the U.S. Gulf of Mexico.

Like the 15K/400°F version that preceded it, the final design for the 20K/350°F capping stack was valve-based. In addition to the shift toward valves, further technology enhancements were incorporated, with an eye toward eventually re-rating the stack for higher temperatures.

To this end, HPHT capping stacks are the first to have full internal-bore corrosion-resistant nickel alloy cladding. In HPHT wells, extreme conditions subject component base metals to corrosion, erosion, stress cracking and other possible material failures. Nickel alloy is commonly applied in the oil & gas, nuclear and aerospace industries, due to its performance in high-temperature acidic environments.

The 20K/350°F Capping Stack was completed and delivered to MWCC during 2018. In 2019, MWCC initiated requalification of the capping stack to increase its temperature threshold to 400°F. As per NTL2019-G03, full independent third-party (I3P) technical qualification of the of the HPHT capping stack at 20,000 PSI and 400°F over a range of static and dynamic well conditions was completed in October 2020, (Table 2) and (Fig. 2.)

Fig. 2. In October 2020, MWCC completed full, independent, third-party (I3P) technical qualification of a 20K/400oF HPHT Capping Stack over a range of static and dynamic well conditions.

OTHER WELL CONTAINMENT EQUIPMENT

While MWCC’s capping stacks are certainly the “crown jewels” of its response portfolio, well containment is not solely reliant on the application of capping stacks. We also steward a broad portfolio of response equipment, including subsea dispersant injection, Interim Collection and Extended Flowback Systems, (Fig. 3.) The Well Control Rule stipulates that if there are circumstances where an incident well may not be able to be fully shut-in from the outset, drillers must have access to capabilities “to flow and capture the residual fluids to a surface production and storage system” while the well is being brought under control. MWCC’s Extended Flowback System was not originally designed to withstand HPHT conditions. When met with this challenge, MWCC engineers initiated an evaluation of options to provide the necessary over-pressure and over-temperature protections.

Fig. 3. Another item in MWCC’s arsenal of well containment equipment is the Extended Flowback System.

SUBSEA COOLING MODULES

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As a result, MWCC commissioned the EPC of two Subsea Cooling Modules (SSCM) in 2018, also through Trendsetter Engineering, to complete our complement of HPHT containment equipment. Each SSCM (Table 3), capable of cooling flowing hydrocarbons by 150°F, attaches to a dedicated outlet on the capping stack via a HPHT-qualified rigid jumper. This enables the safe flowback of well fluids to two Modular Capture Vessels, which, in combination, can capture up to 100,000 bopd and 200 MMscfgd. Cooling is achieved by drawing cold seawater at the seafloor across the heat exchangers, using impeller modules built out of traditional ROV thrusters. The SSCMs were delivered to MWCC’s deployment facility in October 2020, (Fig. 4.)

MWCC is currently in the process of incorporating our new HPHT equipment into our official Functional Specification on file with BSEE, so that member companies can cite the equipment in their well containment response plans for future wells. As per NTL2010-G03, operators need to receive approval for the potential application of any of MWCC’s HPHT equipment on a “site-specific” basis, in advance of drilling the well, taking the specific well conditions into account. To streamline the site-specific permitting process, MWCC is pursuing the submission of “non-site-specific Conceptual Plans” to BSEE through our member companies, providing in advance the supplemental I3P technical verification necessary to confirm well-specific technical sufficiency.

Having the appropriate technology in place for the advancing industry is one thing, but having dedicated response personnel on staff 24/7, constantly practicing for a future possible activation call, is equally important to our response readiness. To this end, MWCC develops and executes a world-class drill and exercise program each year. Our training program follows the Homeland Security Exercise Evaluation Plan (HSEEP), to track and evaluate the readiness of our dedicated Response Team. On average, MWCC conducts 50 trainings and exercises per year that span from seminars to full-scale exercises. In 2020, as part of preparations for the anticipated ramp-up of HPHT drilling programs to commence in 2021, MWCC began exercising the full-scale mobilization of our new HPHT response equipment.

Fig. 4. The SSCMs (Subsea Cooling Modules) were delivered to MWCC’s deployment facility in October 2020.

MOBILIZATION

Having the appropriate technology in place for the advancing industry is one thing, but having dedicated response personnel on staff 24/7, constantly practicing for a future possible activation call, is equally important to our response readiness.  To this end, MWCC develops and executes a world class drill and exercise program each year, inclusive of MWCC members, and key contract partners. Further, MWCC interacts with federal regulators during member-driven exercises annually, allowing them to observe MWCC’s response plans in action.

Our Response Training Program follows the Homeland Security Exercise Evaluation Plan (HSEEP) to track and evaluate the readiness of our dedicated Response Team. The Response Training Program has evolved into a multi-year plan with a majority focus on exercises that build on the prior in depth and complexity. On average, MWCC conducts 50 trainings and exercises per year that span from seminars to full-scale exercises. In 2020, as part of preparations for the anticipated ramp up of HPHT drilling programs to commence in 2021, MWCC began exercising the full-scale mobilization of our new HPHT response equipment.

Fig. 5. in September 2020, MWCC’s Response Team successfully conducted pre-deployment testing of the 20K/400oF Capping Stack, and transported the 256,000-pound stack to dockside.

MWCC’s Emergency Preparedness and Response division spent the first half of the year planning the full-scale dry mobilization of our new 20K/400°F Capping Stack. As is our standard, the exercise utilized the Incident Command System (ICS) for all reporting and communication functions. The exercise plan required the support of 46 Response Team members to complete the successful execution of 24/7 testing and deployment operations over the course of four days. During the exercise in September of 2020, the Response Team successfully conducted pre-deployment testing of the 20K/400°F Capping Stack, transported the 256,000-pound stack to the dockside (Fig. 5.), and sea fastened the unit for offshore deployment. In all, 1,796 manhours were spent demonstrating MWCC’s ability to safely mobilize the stack within committed timeframes. The COVID19 pandemic added a layer of complexity, requiring MWCC’s team to devise and adhere to strict health and safety protocols above and beyond traditional standards.

Qualified observers and evaluators were present during the exercise to assist in measuring its success. Learnings were captured and will be used to further optimize deployment protocols. Foremost of these, MWCC identified areas where execution procedures could be revised or re-sequenced to further accelerate timelines. The exercise additionally tested mission critical contingency plans and exercised night shift operations, which are an often overlooked, yet critical, component of exercise plans.