In April 2017 Pemex E&P completed an offshore exploration well in the Gulf of Mexico with a depth of 18,501ft (5,502m). After review with the Vallourec team, the well design group selected VAM® SLIJ II for their production casing project. The selection allowed Pemex to use a Casing drive system with a drilling shoe, and casing running equipment in one stage rather than running a two-stage liner and tie-back. This solution generated efficiency and cost optimization for Pemex.
As part of the design validation, Pemex engineers and Vallourec checked the VAM® SLIJ II connection fatigue performance and torque performance to ensure the operator would be able to run the string and get to total depth. The open-hole conditions required additional fatigue and torque considerations. Open-hole may vary when running a drill string compared to a casing string. In some cases variations in open-hole dimensions may cause clearance issues, making the running of the casing to final depth more difficult. To overcome this issue drilling companies rotate the entire string of casing, which causes the limits on the connection yield torque to become critical, and operators rely on connections with higher performance values. Our joint technical reviews of all parameters confirmed for our customer Vallourec's solution would ensure the operation would be conducted safely.
The additional rotation and drag associated with running casing in an open-hole also added to the fatigue requirements of the connection. Vallourec carefully reviewed the fatigue performance of VAM® SLIJ II to ensure we met our customer's needs, and that we provided the right connection for the application. Our, and the customer's goal, was to ensure the fatigue experienced was below 20% of the expected fatigue life of the connection. Expected conditions in the well (simulation of number of cycles) were low (about 2%) compared with the calculated resistance of the VAM® SLIJ II connection. The customer was reassured they could rely on an excellent safety factor in fatigue (18%) before reaching the pre-established limit of 20%.
With solid technical information the team provided Pemex with a more competitive option, demonstrating to our customer they did not need to purchase more expensive connections, as VAM® SLIJ II continues to prove its trustworthiness offshore. Thanks to excellent customer service, collaboration with the end-user, and skilled VAM® Field Service teams, Vallourec Oil & Gas Mexico ensured smooth running and good performance of our products at the customer's site. This was the second string Pemex used with VAM® SLIJ II in an offshore exploration well with similar depth.
Contact us to learn more about offshore solutions for the Gulf of Mexico.