Repair and insulation works (RIW) on wells of various complexity levels
During the oil fields operations, there might occur various problems, that worsen the technical and economic oil production rates. One of these problems is associated with the water inflow in the production well.
It is known, that in most cases formations are heterogeneous and have a stratified structure. The most permeable intervals are developed and, consequently, flooded, at the first place.
The technology of repair and insulation works or RIW, developed by our company, helps to reduce the impact of this phenomenon by treating production and injection wells with water-soluble polymers.
As the insulating material, the structured system of the polymeric hydrogel ARGOS is used. The gel-forming composition is based on copolymers of acrylamide with acrylic acid, while production, formation, fresh water and also water, used in the system of formation pressure maintenance and gelling agent is used as solvent.
Such systems are a special kind of solid bodies, combining the properties of solids and elastomeric materials. As solids they keep the form; as elastomeric materials they initiate large elastic reversible deformations under loading.
The insulating properties of such systems are predetermined by their ability to retain in the pores, cracks, caverns, first, by the formation of chemical bonds, while creating high resistance to the water inflow through the gel; secondly, due to the viscoelastic properties inherent in such systems.
This technology solves the following tasks:
• cracks insulation in case of a fractured pore reservoir;
• highly productive interlayers isolation in case of a heterogeneous pore reservoir;
• bottom water isolation;
• annular water removal.
Before the commencement, a number of field geophysical surveys is conducted to determine the water cut source and the integrity of the production string. After detection of the water cut source, a technological work plan is drawn up, which includes a clear sequence of actions determined by the geological service of our company.
The ARGOS structured systems application technology for various types of insulation works can be changed and supplemented with certain operations, such as pumping fixing agents or compositions, plugging compounds, depending on geological characteristics and reservoir properties, production string perforation and others.
Hydrogels technology is a selective method for isolating the water inflow. It has shown good results on wells with high formation water cut level and bottom water isolation works in many regions of Russia, both in the south — the Krasnodar and Stavropol Krai, and in severe weather conditions of High North.
