Great Wall Drilling Drills An Extended Reach Well To Achieve Cuba-s First Ultra-narrow Gap Cementing

On November 2, news came from Cuba that the VDW-1012 well drilled by China Petroleum Great Wall Drilling Engineering Company successfully ran a 219 mm diameter casing into a 244.5 mm diameter wellbore during the fourth well completion operation. The cementing quality It has been verified to be qualified after multiple negative pressure tests. This is the first time ultra-narrow gap cementing has been implemented in Cuba.

Cuba's waters are rich in underground oil resources, and extended-reach drilling is the main technical means to achieve offshore oil and onshore recovery. Well VDW-1012 is also an offshore oil and onshore extended reach well. The well body is designed in an "L" shape and the well depth (total length) is 8,046 meters. The drill bit needs to be constructed vertically below 1,700 meters to go around the seabed, make a nearly right-angle bend, and then be constructed horizontally for more than 7,131 meters to reach the target layer. During the four-way construction, the drilling tools are basically in a "lying flat" state. The cementing operation not only requires drilling tools to push the casing with a total weight of 96 tons to the bottom of the well, but also faces the fact that there is only a 12.75 mm gap between the well body and the casing, making it extremely difficult to run the casing.

In order to ensure the quality of cementing, the company actively carries out guarantee work. Use staged circulation to clean the wellbore to ensure smooth cementing process. Use engineering software to simulate the casing operation to obtain optimal construction data. Develop operating procedures and conduct training to clarify personnel division of labor and risk prevention. During the casing running process, the platform manager was on duty at the wellhead to eliminate every possible risk.

With the full cooperation of the employees of the GW91 team and relevant parties, it finally took 80 hours to lower the 1,797-meter liner string to 5,810 meters and successfully completed the cementing operation. For this reason, the Cuban Petroleum Company sent a letter of commendation to express its affirmation.