Currently there are a large number of companies and a large number of provided by them stimulation of oil and gas production technologies.
We can help your company to choose the most effective technology for fracturing or acidizing. We will help you to choose the best candidate well for hydraulic fracturing operation or acid treatment. Specialists of "TRIAS" know how to achieve high fracture conductivity, how to effectively place proppant agent, how to put the well into operation after well stimulation. Our experts will help to draw up a program for carbonates and sandstones acidizing, will indicate which reagents to select, how to deal with the deposition of paraffin and asphaltenes, how to deal with emulsification and secondary reactions products.
Our engineers know how to make the production rate of well be much more than before stimulation. We can defend your goals from errors and omissions of service companies when planning and carrying out hydraulic fracturing, acidizing of bottom-hole zone.
Customer benefits:
• Reducing total cost of stimulation works.
• Incremental production in stimulated wells.
• Reduction of repair hours and time spent putting the well into operation.
Design and control of stimulation using hydraulic fracturing
Hydraulic fracturing - a method of hydrocarbons inflow stimulation and increasing of injection capacity of wells. The method consists in creating a high-conductivity fractures in the target reservoir for ensuring the flow of produced fluid (gas, water, condensate, oil and mixed compositions) to the bottomhole. Technology for implementation of hydraulic fracturing involves pumping down borehole with the help of powerful pump tracks of fracturing fluids (water- or petroleum-based gels) at pressures greater than target bed fracture pressure. To maintain the fracture in an open state the propping agent is used - proppant.
After hydraulic fracturing the well production rate usually increases sharply. The method allows to "reviving" idle wells where oil production is not possible by conventional methods or not sufficiently remunerative. In addition, at the present time the method is used for development of new oil reservoirs, where oil recovery by conventional methods is unprofitable due to low flow rate.
Usually hydraulic fracturing and other stimulation methods are specialization of oil service companies such as Halliburton, Schlumberger, BJ Services, CalFrac, Trican, KatOil.
Designing and control of stimulation using chemical methods
There are three main technologies of acid treatment:
• Acid washing (not a treatment of reservoir)
• Acid bath
• Matrix acidizing
• Acid Fracturing
Acid washing goal is simple – clearing of tube side and downhole. Reservoir treatment is not provided.
Acid bath - the most commonly used method of cleaning bottom-hole area, this method consists of injection of reagent to the downhole and aging of the reaction to clean the downhole.
Acid treatment of the rock matrix is injected - acid injection at a pressure below the fracturing pressure (minimum mechanical stress in the rock).
Acid fracturing - this acid injection at a pressure above the fracturing pressure (minimum mechanical stress in the rock).
Acid treatment of the rock matrix
Acid treatment of the rock matrix is used in carbonate rocks and sandstones. In sandstone acidizing treatment of matrix is aimed at dissolving of particles damaging the bottom-hole area and perforations.
Theoretically acid is filtered in a porous medium, dissolving the solids in the pore channels, which prevent the movement of a reservoir fluid, the acid dissolves the solids in pores, pore channels and along pore surfaces.
Most of the acid is consumed by reaction with minerals and the particles in pores. Therefore, in sandstones acidizing treatment is mainly used to clean the downhole. It is difficult to expect an increase in productivity in the sandstones, conducting acid treatment of matrix in layers without damage zone.
In carbonate reservoirs in the process of acid treatment the so-called "wormhole" is generating or caverns that penetrate far beyond the bottom zone or are an elongation of the perforations. "Wormhole", achieved by hydrochloric acid dissolving carbonates resembles the channels created by worms in the soil; because of it they are so-named.
Very often the acid forms one single "wormhole", without any branching. This occurs, for example, in the case of using a strong hydrochloric acid solution. Weak acids such as acetic produce more branched channels, which may produce a result only in certain cases. Type of "wormhole", of course, depends on the injection rate, temperature, reaction abilities of rock around the wellbore.
Acidizing treatment in carbonate reservoirs is mainly used to reduce the impact of damaged formation zone on the productive capacity of well. In the absence of damage the acid treatment of matrix results in no more than a two-fold increase in productivity.
Acid fracturing.
Acid fracturing is mainly used in carbonate reservoirs, including limestone, dolomite and so on. It is used to increase the productivity of wells with damage bottomhole zone and/or to stimulate the area without damage. Acid fracturing - an alternative of matrix acid treatment and hydraulic fracturing. The goal is the same - the creation of long highly conductive channels in the reservoir, however, extending farther beyond the damage zone, then while matrix acid treatment. The essential principles of distribution and fracturing are the same. The difference between the acid fracturing and formation fracturing is noticeable in relation how fracture conductivity is created and maintained thereafter.
While formation fracturing conductivity of fractures is maintained by injection of solid materials such as sand, bauxite, ceramics into fractures, is having a common name - proppants.
While acidizing treatment the acid is injected into the fracture created by the H.V. fluid, or the acid itself. Along the way she reacts with the rock, dissolving it unevenly, creating a surface with well-developed relief that prevents a crack from the "collapse". Subsequently, the crack is healing, but highly conductive channel remains.