Kazakhstan journal for oil & gas industry

The article is devoted to the issues of subsidizing, which are very relevant in the light of recent discussions on improving the mechanisms of direct and implicit price subsidies. The paper discusses the issues of subsidizing of socially important goods, which include, for example, oil refinery products, liquefied gas and others, provides formulas for the amount of subsidies, determining the cost of subsidizing, the trader's margin from the exchange price. These calculations will contribute to the correct planning of regional budgets for subsidies.

The number of fields that have reached stage IV of development is increasing every year. Due to the high level of water cut, it becomes difficult to develop residual recoverable reserves. Also, due to the increase in the share of high-viscosity oils in Kazakhstan, the task of their effective development becomes more complicated. The development of terrigenous reservoirs, which have a complex structure and contain high-viscosity oil, is usually characterized by low production rates and oil recovery factors. Currently, technologies that ensure high efficiency in the development of such deposits are very expensive.

In this regard, the development of oil fields through the commissioning of horizontal wells is becoming more in demand, capable of increasing the efficiency of developing oil reserves. Drilling of horizontal wells is considered for:

• floating reservoirs with low reservoir production coverage due to high water cut. High levels of water cut are due to breakthroughs of bottom water and degraded technical condition of wells (annular flows, wear and leakage of the string, depressurization of previously isolated intervals and poor quality of cement adhesion);
• thin layers, not involved in the production. Basically, thin layers are not involved in the production due to the low performance of vertical wells;
• on horizons with high-viscosity oil. In highly viscous horizons, the injected water breaks through to the bottom of production wells along the base of the reservoir when the horizon is not developed.

Also in the Atyrau region, fields with hard-to-recover reserves (fields with high oil viscosity and low permeability of the productive horizon) are being developed. It is in such fields that horizontal wells have already been drilled and will be drilled in the future.

The presented article discusses the results of the analysis of the drilled horizontal wells in the North Volga and Aknur oil fields.

Modern seismic exploration still faces the challenges of automating processes and increasing the reliability of work results, especially in regions with complex geological conditions. An important place in the cycle of seismic surveys is occupied by the stage of kinematic interpretation, the main purpose of which is a detailed understanding of the structural features of the geological section and obtaining a reasonable geological model of a particular region of study.

The cost of an error at this stage of the work is quite high, but the interpretation processes require significant labor costs, and the results often contain errors. Standard algorithms and methodological approaches do not fully provide solutions to the full range of tasks, which necessitates the search for new approaches to the interpretation of seismic data.

In recent years, there has been increasing interest in attracting the capabilities of artificial intelligence to solve production problems. New approaches to solving the problems of the stage of kinematic interpretation of seismic data based on the use of artificial intelligence through machine learning and deep neural networks are proposed:

– technology of elimination of irregular noises of the total seismic data to improve the quality of the initial seismic material and simplify the stage of structural interpretation;

– technology of probabilistic forecast of disturbance systems and obtaining a detailed tectonic model.

Theoretical foundations are presented and the results of applying technologies on a series of real production projects are demonstrated, which confirm the advantages of using neural networks in interpretation to eliminate subjectivity and significantly reduce time costs at the stage of structural constructions in various geological conditions.

The article presents the results of the implementation of technologies based on the use of the thermal effect of a number of exothermic reactions occurring in reservoir conditions between the components of the composition injected into the reservoir. The main direction of using chemical compositions based on available inorganic and organic salts is the heat fixing of RCP-proppant (polymer-coated proppant) in hydraulic fractures (about three hundred wells in the Volga-Ural region) in terrigenous reservoirs. Technical solutions are proposed to combat the absorption of thermosetting compositions in wells with low reservoir pressure. Another option for the use of thermosetting compositions in conditions of consolidated reservoirs is to increase the oil flow rate of production wells due to an increase in the permeability of bottomhole formation zones due to the dissolution of asphaltene, resin and paraffin deposits, as well as an increase in the mobility of reservoir oil due to a decrease in its viscosity as a result of the action of released heat and reaction gases.

There is a growing number of fields in the world that are at the last stage of development. These fields are characterized by high residual oil saturation and water saturation. In addition, newly discovered fields are characterized by the content of high-viscosity oil. The development of such reservoirs is associated with great difficulties. This paper considers a combined technology that allows to intensify oil production from oil reservoirs. The studies were carried out on a homogeneous reservoir model in the following sequence. First, we carry out the displacement of oil by injecting electrochemically modified water (catholyte). Then we pump in a gas-liquid emulsion slug, which we push through with water or catholyte. The combined action of the emulsion and catholyte leads to an increase in the pressure drop and a change in the filtration rate. As a result, this leads to an increase in the oil recovery factor.

The development of fields that are at a late or final stage of operation is carried out mainly with the use of downhole sucker rod pumps. The most characteristic failures for these installations are rods’ parting-twist off and malfunctions of pump valves. The methods of eliminating these accidents vary significantly – the parting or twist off of the rods involves lifting of the downhole equipment, and the "sticking" of the shut-off valve assembly of the pump is eliminated by "resuscitation" of the downhole equipment (flushing with water, hot oil or solvent). An error in fault identification leads to incorrect planning of work to restore the operability of the downhole equipment and, as a result, to economic losses.

The cause of malfunctions of the downhole equipment of downhole rod pumping units, as a rule, is determined by analyzing dynamograms. However, in many cases dynamograms do not allow to distinguish the lower twist off of the rods from the malfunction of the valves of the rod pump. In the presented work, a method for the operational determination of the parting or twist off of rods in the well is considered, which consists in creating an electrical circuit "rod string –tubing string" and monitoring its integrity. To determine the type of malfunction, the synchronization unit measures the resistance of the system on the dielectric insert via the electromagnetic channel. In case of parting or twist off of the rods, the electrical resistance of the "tubing-pump-rod string" circuit will be much higher (more than 2 ohms) than in the absence of this failure (0...2 ohms).

-