Chevron has taken up the Congo River Canyon Crossing pipeline project. The Congo River crossing is Chevron’s largest-ever well intersection and it is the most technically challenging aspect of the pipeline project. Chevron completed the drilling of a well-intersection beneath the Congo River submarine canyon. To create the intersection, two wellbores were drilled simultaneously from shallow water platforms located on each side of the canyon. One of the platforms is situated in the Democratic Republic of the Congo while the other platform is at Angola. When completed, the pipeline will be approximately 87 miles (140 km) in length and initially transport up to 250 million cubic feet of natural gas per day. The Democratic Republic of the Congo and Angola approved the project that will transport natural gas from Angola’s offshore Blocks 0 and 14 to the Angola LNG Plant, the country’s first LNG project.
Several high-end, innovative technologies such as active magnet ranging technology was used to direct the drilling assembly so that the wellbores merged precisely on a target roughly the size of a basketball
The Congo River Canyon Crossing Pipeline Project includes an 87 mile — or 140 kilometer — pipeline that is routed under the Congo River seabed canyon as well as two locally constructed platforms on either side of the canyon. To complete the Congo River well intersection, Chevron installed jack-up drilling rigs to offshore platforms on both sides of the Congo River submarine canyon. The rigs simultaneously drilled wells down to a vertical depth of 4,872 feet then transitioned from vertical to horizontal and intersected mid-point beneath the canyon. An active magnet ranging technology was used to direct the drilling assembly so that the wellbores met 2 miles away in a target smaller than a basketball. A magnetic sensor was run on the drill string on one side, while a powerful magnet, located behind the drill bit, was rotated by the other rig. The signal from the rotating magnet was used to calculate the distance between the drill bit and the sensor. This calculation allows to update the well plan and corrections to the downhole steering device until the wellbores were carefully merged. Once the path was successfully opened, more than 23,000 feet of steel casting was run into the wellbore — in a first-of-its-kind two-rig push-pull operation — to create a continuous natural gas pipeline from one platform to the other. The platforms on either side of the canyon will remain in place to identify the pipeline’s position
Source: Chevron
