Pontoon Drilling Rig for Fenog Nigeria Limited


Prime Drilling Horizontal Directional Drilling Rigs are in operation all over the world and defy the most difficult environmental conditions every day. Nevertheless the specific requirements of the West African company Fenog Nigeria Limited (FNL) presented a completely new challenge for the HDD-Rigs manufactured by Prime Drilling. With the installation of pipelines for oil production in the Niger delta both man and machine are frequently faced with a big problem: How can the stability of the rigs used be stabilized within one of the biggest swamps in the world and how can the HHD Rigs be prevented from sinking into the soft ground ?



The company; Fenog of Nigeria Limited is of great economic importance in Nigeria, a country whose export revenues and national income mainly arise from oil production, and is a major employer of the local population. Their headquarters are located in the city of Warri, which is an important centre for the extraction and transit of oil on the West African continent and has more than half a million inhabitants.

The first Horizontal Directional Drilling Rigs supplied to long standing customer Fenog were equipped with standard crawler carriage. With the Niger delta the rigs were transported by barge to the respective job-site. The sites where the rigs were used had a wooden underlining covered with excavator mats to prevent the HDD machines from sinking immediately into the soft ground. However, after a certain time the heavy rigs, which weighed several tons, were in danger of sinking into the swamp despite the specially prepared standings.



The Prime Drilling designers, who are known and highly respected for their creative ideas and innovations, have developed a drilling rig with an extra wide crawler track carriage. This innovation was supposed to lower the ground pressure in order to avoid sagging of the HDD rigs due to the swampy soil. Indeed Prime Drilling managed to reduce the ground pressure by 50% from 8.7 kn/m² auf 4.7 kn/m². Due to this enormous progress the HDD rigs could be operated more easily and more effective.

Despite the new crawler track carriage the rigs still had to be transported by additional barge. The Prime Drilling staff thus conducted thorough research to find a solution for this problem and finally came up with a drilling rig that is ideally suited for use in swamps all over the world. The excavators used at the job-sites in the Niger delta put Prime Drilling’s designers on the right track where they equipped the HDD rig with floating bodies similar to the Nigerian “swamp excavators”. These pontoons were to prevent the now more or less floating HDD rig from sinking. In addition the rig was now movable on site without the need for an additional barge. The pontoons themselves consist of two hollow steel bodies each, that are firmly linked by a brace. The single tracks of the crawler enclosing the pontoon body are made of equally small hollow bodies and help secure both the flexibility of the rig and to increase its uplift. The ground pressure of this innovative almost amphibious drilling rig is thus reduced from 4.7 kn/m² to 2.0 kn/m²



The unique HDD-Rig has proved to be a great success for Prime Drilling, its customer Fenog and the extensive drilling projects in the swamps of Nigeria. Owing to this revolutionary innovation, the pipelines being installed over thousands of kilometres in the Niger delta can be pulled in faster, easier and more economically in the future.


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