Demanding performance requirements
Baker Oil Tools
The number of offshore projects in the world that must contend with the chall-enges presented by high-pressure, high-temperature (HP/HT) conditions is growing, and the rate of growth of these projects may increase if, as many expect, deep shelf royalty relief in the Gulf of Mexico is extended to existing leases.
The demanding performance requirements for HP/HT completions and the fact that the exposure level can easily reach $45 million per well dictates that special consideration is required, not only in designing the wellbore and the equipment within it, but also in how the project is executed, from procurement through installation.
Continuity of personnel committed to the project and ongoing, accurate communication, both between the operator and the completion contractor(s) and among project team members in all involved companies, are essential to successful HP/HT completion projects.
Effective project management is a critical success factor for any HP/HT development. The selection of the completion equipment and service contractor(s) for HP/HT projects must be handled differently than for more standard wells. The fit-for-purpose nature of the completion equipment required for HP/HT projects necessitates earlier selection of contractors to afford adequate product development time. Also, the unique application of HP/HT completion equipment often necessitates an early commitment from the end-user for product development to be commercially viable to its providers.
The QCP governs what inspections will be made on each component of procured tools.
Industry publications have generally defined an HP/HT well as one with combined pressure and temperature conditions exceeding 10,000 psi and 300° F. However, several projects have pushed performance requirements to 15,000 psi and +400° F. Experience gained from several high-profile developments indicates that "off-the-shelf" completion equipment is inadequate for HP/HT conditions. Fit-for-purpose equipment is often the only solution in the different operating envelopes for "standard" equipment and those required for HP/HT equipment.
In selecting a completion provider for an HP/HT project, the operator must evaluate a potential provider's current equipment design technology and product development capabilities as demonstrated in similar products and applications, and the application of that technology to the requirements of a new HP/HT project. The ability of the provider to deliver a new product to meet the requirements of a specific HP/HT project is one of the primary factors to ensuring the success of the project.
The operator should understand each potential provider's design philosophy, including the approach to applying safety factors, accounting for temperature effects, forming assumptions reg-arding worst-case loading conditions, and interpreting applicable regulatory requirements pertaining to the equipment design. The operator also should dedicate resources to perform a thorough analysis of each supplier's health and safety record and systems, product offerings, product design and development capabilities, prior field performance of similar equipment, ability to meet the completion objectives, delivery capability, and the commercial value of each respective offering.
HP/HT service conditions require that both the operator and the completion provider exert a greater focus on managing the development and procurement of completion equipment than would be the case for more standard well conditions.
Clear communication between the operator and completion provider is essential to establish a common understanding of the performance expectations and design limitations. To this end, the importance of selecting and assigning the right individuals to an HP/HT project to work on the project from start to finish cannot be overstated. Ideally, the operator and completion provider should each devote dedicated resources with single point contacts who will coordinate the project from feasibility through installation.
When the completion providers have been selected, the individuals involved in the front end can use their established channels of communication to ensure that project objectives are clearly understood throughout the provider's organization. To ensure clear project direction and an understanding of the project requirements and deliverables, project kick-off meetings, progress updates, and design reviews can be managed with operator involvement, which is also extremely valuable in the development and manufacturing process. For example, operator participation in design trade-off discussions can help balance project requirements with the provider's design considerations. Any manufacturing issues that arise also can be managed to avoid delays and ensure that the HP/HT project requirements are weighed with provider considerations to arrive at an optimum project solution.
A rigorous approach should be taken to identifying equipment ratings and performance requirements to ensure safe and productive performance of completion equipment in specific HP/HT environments. Both op-erator and provider must understand the performance requirements and the process by which the design is created and tested to meet those requirements.
To identify unique equipment requirements for an HP/HT project, perform engineering feasibility evaluations and conduct supplier technical and commercial evaluations on an accelerated schedule. Dedicated single points of contact for both the operator and the completion equipment and service providers should be established during the preliminary evaluation of completion design requirements.
Ideally, these individuals will remain involved through the duration of the project. The interaction between the operator and completion provider in identifying equipment requirements establishes communication channels that will naturally progress throughout the project.
With suppliers selected and new product development projects ready to kick off, the first step is to clearly define a set of operational parameters and performance rating requirements for the new equipment to be developed. While preliminary equipment requirements already exist, a successful, timely new product development will have a set of approved design specifications that are "set in stone" as soon as possible.
Changes in the performance requirements can have significant impacts to product cost and to the equipment development schedule. In addition to making every effort to define accurate design specifications and performance requirements, the supplier must ensure the engineering feasibility work is accurate so the equipment can be delivered as proposed.
To date, successful new HP/HT product development projects have been characterized by operator involvement and teamwork with the equipment supplier throughout the process. End-user involvement in equipment design reviews, status meetings, defining test parameters and acceptance criteria, reviewing test results, and third-party design verification can ensure that the deliverables for new product development projects are met.
Involvement with equipment supplier
End-user involvement in equipment design reviews ensures that the operational requirements for the equipment are addressed before the design is released for prototype manufacture. Indepen-dent third-party design verification is an added measure frequently employed to gain confidence in the equipment design and the application of the design in a specific HP/HT environment.
Factory acceptance tests, type tests and other special, one-time prototype test requirements are often incorporated to ensure that newly designed equipment does in fact perform as intended. The extent of end-user involvement discussed here is not typical for standard wells. This approach has proven to result in successful HP/HT completions.
A key concern in any high-profile completion project is that equipment is manufactured, assembled, delivered, and installed correctly. A comprehensive quality control plan (QCP) assures the operator that the production equipment is built to specifications and agreed parameters. The QCP is the governing document, per ISO guidelines, that dictates all actions taken during the procurement process. The QCP also dictates what records and documentation are kept for future reference. These plans are often negotiated between customer and vendor to ensure that both parties understand and agree on steps to be taken to inspect and document equipment manufacture.
Additionally, on high-profile HP/HT projects, third-party inspection is employed by both the procurement and supplier parties during the manufacturing and assembly stages. It is also employed at times during the design process and verification testing stages.
If the end user prefers to have a review performed at the design stage, special care should be given to those selected to perform the review. If the engineers who review the calculations are not familiar with how they are applied to a particular tool's function, confusion can result, as can communication issues between parties and project delays.
Prototype testing is one of the most critical stages of the procurement process. Several industry-wide standards have been adopted to qualify equipment. Examples for downhole completion equipment include API 14A, ISO 10432, and ISO 10417 for downhole safety valves and ISO 14310 for the development of packers and bridge plugs. A similar standard is being developed for wireline-conveyed flow control equipment. Equipment for HP/HT projects usually is tested to the most stringent standards set forth in these documents.
The QCP governs what inspections will be made on each component of procured tools. Parts for high-profile projects such as HP/HT developments are usually inspected and checked three to four times by both the manufacturer and third parties to help minimize or eliminate human error. These inspections and reviews continue through assembly and shipment.
Quality control continues at the field location as well. Locations often have governing procedures for handling equipment throughout installation. High-profile projects also may have specialized instructions for all equipment procured for their wells.
The benefit of dedicated HP/HT project resources is perhaps more evident at the equipment deployment and installation phase than at any other phase in the project. Every safeguard and process from earlier stages of the project is wasted if actual deployment of the equipment at the well site is flawed.
Shared planning and commitment between operator and contractor is essential for on-site personnel to flawlessly execute installations. Similarly, having the right knowledge at the well site is paramount to a successful completion. When people understand their roles and responsibilities as well as the limitations of the equipment, mistakes are avoidable. In the high-profile well arena, this is the ultimate goal.
HP/HT project installation is treated differently than standard wells. Rather than moving to the next development project, operator and service company planning resources dedicated to an HP/HT project continue to be involved during the drilling and completion of the wells. Retention of individuals familiar with the project through the installation phase is a key management strategy to ensure that the information transfer is complete and the wells are successfully brought into production.
A dedicated service center and field technician personnel should be a part of the team that plans the completion procedure. Intimate knowledge of how equipment was designed, tested, and assembled can prevent mishaps during installation.
Some end users also have found it beneficial to have a complete run-through of the completion procedures with all the service technicians involved. This allows people who will be working together on site to become familiar with one another.
Several of the same principles followed in earlier steps are applicable here. Experience has shown that a written, dedicated quality plan adds value and assures performance.
The Jade development is located in the Central Graben area of the North Sea in the UK sector, 170 mi east of Aberdeen, in 260 ft of water. The development is operated by ConocoPhillips (32.5%) with co-venturers BG International Ltd. (35%), ChevronTexaco (19.9%), Agip UK Ltd. – a wholly owned subsidiary of Eni S.p.A. – (7%), and OMY UK Ltd. (5.5%). The field has estimated gas condensate reserves of 36 MMbbl of oil and 415 bcf of gas. The bottomhole reservoir pressure for the field is 12,700 psi, with maximum bottomhole temperatures of 380° F. Produced fluids are gas and gas condensate of 46° API with impurities in the production stream of 3% mol CO2, 25 ppm H2S, and up to 24% wax.
Field development called for a tie-back producer, tie-back cuttings re-injection well, and three new drill producing wells. This was later modified to four new drill wells after the decision was made to forego tie-back of the appraisal well for production as originally planned. Well design requirements called for production capability of 90 MMcf/d with 12,500 b/d.
Phase 1 of the project initially was planned for a tie-back production well, a tie-back cuttings injection well, and three new drill production wells. Because of damage observed on inspection of the tie-back well, it was decided that the tie-back production well would not be attempted during Phase 1 of the Jade development.
Due to the success of the Jade project and the decision not to attempt the tie-back production well, Phase 1 of the Jade development actually included the tie-back of the cuttings re-injection well and four new production wells drilled in the central Jade block. At the time of writing, due to the success of the Jade central block wells, the phase 1 development has been extended to include an exploration well in to the Jade northeast flank. At this stage it is uncertain how many wells will be required in the Phase 2 development, but after the current well is completed (30/2c-J07), there will be only five slots available on the template.
As completions contractor, Baker Oil Tools provided a dedicated core team of personnel at both the on-site office and the manufacturing facilities. The personnel worked in tandem with an assigned core team of personnel from the Jade development team. All correspondence took place through these point contacts. Bi-weekly meetings were held to track progress and manage the project. The strategy used to manage the project was to assemble a dedicated group of end-user and supplier personnel to manage the project with a team approach.
The wells for the Jade development are designed using 9 7/8 in. casing (special casing with an OD of 10.03 in.) with a 7 in. x 5 in. production liner. Also, 5 1/2 in. tubing is tied back with a seal assembly in a 6 in. polished bore receptacle (PBR) with 5 1/2 in. flow control nipples above the safety valve and below the PBR. HP/HT completion equipment development requirements included a 5 1/2 in. tubing retrievable safety valve with 11,000-psi pressure rating and 400° F temperature rating and 15,000 psi/400° F flow control plugs and nipples. The completion used a liner top packer to land the liner and provide a polished bore receptacle for the tubing seal assembly.
Each safety-critical tool used in the project, the safety valve, flow control equipment, tubing seal assembly, and polished bore receptacle, and liner top packer and liner hanger equipment, underwent a complete third-party design verification. Once the designs were approved, a testing program was devised with input from all parties involved. Each tool was qualified to meet the expected downhole conditions.
An example of the qualification testing that was completed for the project is the flow control equipment. The plugs were tested to a qualification test program developed with end-user input, to verify the function of the equipment at rated pressure and temperature of 15,000 psi and 400° F. A third-party inspector witnessed the qualification testing.
The Jade project followed a quality control plan similar to that discussed earlier in this article. All materials were documented and verified. Positive material identification was used to ensure that actual materials matched the material documentation. Separate safety-critical and non-safety-critical quality plans were utilized. Third-party inspectors witnessed one hundred percent of the inspection for all critical components.
The completions were run successfully. Currently, four wells have been completed successfully with additional wells in progress.