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Drill pipe-based completion workover risers lower costs and increase efficiency

MaXit connection enables drill pipe-based CWOR to overcome the limitation of casing-based CWOR.

Jul 22, 2019

The deepwater and ultradeepwater sectors remain critically important to future oil and gas development but also economically challenged in the current market environment. OCTG completion workover risers (CWORs) have been cited as an alternative to drill pipe-based CWORs due to the inherent challenges of designing drill pipe connections that can withstand the harsh service conditions of deeper, higher-pressure prospects. Though their upfront cost is less expensive than drill pipe-based CWORs, their total cost of ownership is significantly higher. Fortunately, drill pipe-based CWORs have advanced technologically and are now a viable, cost-effective solution in even the most challenging completion and intervention operations.

The MaXit™ connection from our Grant Prideco business unit is a large-diameter, gas-tight, rotary-shouldered connection that incorporates metal-to-metal radial seals, sulfide stress cracking-resistant welds, and high-strength, sour-service metallurgy. After rigorous testing to the standards of API RP 17G and ISO 13628-7, we determined that pipe incorporating the MaXit connection was more than adequate for CWORs. Though casing-based CWOR products are often lighter weight, have larger drifts, and a lower initial capex requirement, they cannot be made up and broken out nearly as much and have a dramatically higher recut rate than drill pipe. Furthermore, unclear inspection criteria, specialized equipment, and complicated R&M processes make dealing with a casing-based CWOR time-consuming and expensive.

See the full cost analysis and learn more about why drill pipe-based CWORs are well worth the consideration in the current marketplace in our recent feature World Oil article with coauthors at Workstrings International. We explore the benefits of drill pipe-based CWORs, notably a 70% cost of ownership reduction over the life of the product versus a casing-based CWOR and a much-improved time for running and handling of the pipe.

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