Specialists from Perm National Research Polytechnic University (PNRPU) have created a polymer gel based on xanthan, designed to combat the loss of well integrity in oil fields. Xanthan is a white, odorless powder with high penetration ability and low cost. It is typically used to clean wells of sludge — waste or raw materials resulting from the engineering development of a mining product, but Perm scientists have found another use for this biopolymer, according to the university's press service.
In oil extraction, two types of wells are typically used: production and injection wells. The former are needed for direct extraction, while the latter are used to improve oil recovery. This is achieved by injecting water into the formation, which helps push the oil towards the well. The problem is that fractures occur in the rock, reducing the efficiency of oil recovery. This usually happens in oil fields that have been in use for more than 50 years. The development created by the scientists is necessary to solve this problem.
The composition seals fractures and penetrates shallowly into low-permeability rock. A gel-like structure forms within 24 hours, blocking the movement of formation water through the fractures.
Xanthan is easily extracted and inexpensive, so scientists decided to use it as a water-insulating gel. Unlike non-selective compositions, which are actively used in oil fields, it does not block the flow of oil into the well.
The gel is pumped into the formation using cementing units. PNRPU reported that the developed gel has good viscosity, so the cementing equipment does not need to exceed the permissible working pressure. In addition, the development by Perm scientists is universal: it can be used in conditions of highly mineralized water, as well as in a wide temperature range.
Earlier, www1.ru wrote about how the manufacturer of Topol and Yars missiles replaced imports of hydraulic fracturing fleets for oil production. The Russian development has a number of advantages compared to Western counterparts.