Today, SCF Endeavour — an icebreaker serving the Sakhalin Energy offshore platforms — with unique equipment and unusual cargo on board left the Sakhalin Western Sea Port and headed for the north of the island towards the LUN-A platform.
It will be the first time in the history of the Sakhalin-2 project and also in the world history that a Russian ice-breaking supply vessel will install filters to prevent sand from sloughing into the gas producing wells.
“During gas production, the pressure in the reservoir drops and the rock begins to collapse,” says Kirill Gnatenko, Sakhalin Energy Senior Wells Workover and Completion Engineer. “Over time, sand sloughs into the well, which decreases its yield. To address this problem, in 2016 we began to complete gas wells using gravel packing in an open hole, and have been doing this ever since. This helps to prevent the sloughing of sand from the reservoir, which would lead to erosion of downhole and surface equipment.”
Specially for this operation, a module weighing 550 tonnes was installed on the deck of SCF Endeavour. By the way, 550 tonnes is the weight of the equipment alone. This figure does not include the weight of sand and carrier fluid (gel). If the tanks are filled to their full capacity, the weight of the complex will reach 1,400 tonnes.
In December 2018, Sakhalin Energy made a decision to upgrade SCF Endeavour in order to perform all these works without involving foreign ships in the operations.
Alexander Lukashik, Sakhalin Energy Marine Operations Manager, assures that now the company can carry out the entire cycle using its own resources, thus saving considerable amounts of time and money. “In addition, working with new equipment is a new experience for the crew of the vessel and the seaport, too,” he added.
The complex is fully automated, which minimises the number of required operating personnel. Monitoring and control are carried out from the control room.
Upon arrival at the work site, the crane will lift a flexible stainless steel hose from SCF Endeavour to the connection point on the first deck of the LUN-A platform, which is at the height of a 13-storey building. Then a mixture of sand and gel will be fed through the hose. Every step of the operation has been thought out to ensure maximum safety during work. For greater stability of the vessel, another independent dynamic positioning system has been installed on SCF Endeavour in addition to the existing two, which will keep the vessel in one place during the loading.
“The up-to-date complex for sand control in wells, installed on our vessel, also allows us to perform other kinds of work, including hydraulic fracturing operations. All this increases the profitability of hydrocarbon production,” said Vladislav Platonov, the captain of SCF Endeavour. “Our task is to bring the vessel to the point of destination, to wait until the platform is ready, to go up and stay near it until the end of the operation. This task is different from the ones we have performed before, but we will definitely cope with it,” the captain added with confidence.
After the packing of well filters is completed, the high-tech module will be disassembled and sent to storage until the next such operation.