China sets two world records in deep-sea energy exploration in Bangladesh

A multi-functional modular seabed trencher developed by a Chinese firm has recently completed the laying of over 100 kilometers of the first offshore pipeline project in Bangladesh, setting world records in "sea land directional drilling crossing" and "deep-sea trench behind the channel," the China National Petroleum Corporation (CNPC) announced Saturday.

The seabed trencher was self-developed by state-owned China Petroleum Pipeline Engineering Co (CPP), which is a professional company specializing in constructing oil and gas storage and transportation infrastructure, under the China National Petroleum Corporation, reports Global Times.

The installation of the marine pipeline project Bangladesh's first marine pipeline project , one of the key projects under the Belt and Road Initiative, needs to complete six directional drillings and reach a buried depth of 11 meters to avoid the commercial and naval waterways, making the unprecedented difficulty in the history of world marine engineering, CPP said.

Directional drilling is a technique oil-extraction companies use to access oil in underground reserves. The term deep-sea trench, also known as an oceanic trench, refers to any long, narrow, steep-sided depression in the ocean bottom at depths of approximately 7,300 to more than 11,000 meters. 

According to reports, the normal depth of trench digging in the offshore industry is 1.5 meters to 3 meters under the seabed, and reaching 5 meters is already a difficult project for the industry.

To deal with technical difficulties, CPP has carried out independent innovations and upgraded trenching machines to achieve a maximum digging depth of 11.9 meters, mastered the underwater millimeter-level docking technology of offshore single-point mooring and adopted the original technique that ensured a 100 percent success in one-time drilling.

As an important oil and gas storage and transportation project in Bangladesh under the Belt and Road Initiative, the project was launched as Bangladesh is not capable of handling large vessels carrying imported crude and finished oil due to low navigability of a key river channel and constrained facilities at the main seaport in Chittagong, the Xinhua News Agency reported.

In December 2016, Bangladesh reached an agreement with CPP for engineering, procurement, construction and commissioning for the installation of single point mooring with 220-kilometer-long double pipelines, including building a 146-kilometer-long offshore pipeline and 74-kilometer-long onshore pipeline to carry imported oil from sea to a refinery in Chittagong district.

The project is expected to have an annual unloading capacity of 9 million tons.