Use as a potential base for increasing the level of exploration and the subsequent active development of hydrocarbon resources associated with low-permeable carbonate reservoirs is associated with the need to actively develop methods for extracting and then intensifying the development of such deposits. The current stage is characterized by active development and modification of development methods and enhanced oil recovery of weakly drained and low-permeable reservoirs.One of these methods is acid fracturing and variations.
This paper proposes the method of approximation incomplete recovery of pressure at Well-test. The authors proposes simplified three-parameter regression model. A procedure is described finding optimal parameter of the empirical formula. Limits of applicability are described.
In the conditions of the digital oil and gas economy, the use of analytical research methods in the field of investment activities of oil companies is becoming increasingly important. The article discusses the mechanisms of economic and cost-effective engineering for the development of oil and gas resources. The Graf information- logical system was created and tested for economic and profitable modeling of oil and gas investment projects both in Russia and abroad. ILS "Graf" controls the correctness of the logical conclusion on the basis of the database and knowledge base of the problem area in order to comprehensively evaluate the options for the development of oil and gas fields on the basis of expert knowledge. The relevance of the study is due to the need to create mechanisms for the economic assessment of oil and gas resources in the dynamic development of the digital oil and gas economy of Russia.
The article describes one of the solutions of undercompensation zones identifying issue on the multilayer objects. The solution is based on the construction of a simplified geological model of each layer with unknown resistances between the blocks of the model.The optimization issue of the fluid volumes distribution for identifiable resistances on single and multilayer objects is solved, by analogy with the redistribution of the electric potential in electrostatics.On the basis of developed solution, maps of the injection undercompensation wereconstructed for Minnibaevskaya area and the 3rd block of Berezovskaya area.
Liquid hydrocarbons (LHC - oil and retrograde condensate) are shown to be located in dynamic, open to flow part of pore volume in gas-saturated productive formations of gas-condensate and oil- gas-condensate fields (GCFs and OGCFs). Justification and experimental (physical) modelling of LHC recovery techniques from gas-saturated formations of GCFs and OGCFs at late development stages are shown to be reasonable because of large LHC resources and need for enhancement of HC-components recovery, as well as elongation of HCs production. Experience is presented and methodology is justified for experimental modelling of a HC system life-cycle at Vuktyl OGCF during the depletion period. On a reservoir core model, fluid saturation corresponding to the initial state of the Vuktyl reservoir system was reconstructed, including LHC (reservoir oil), and modelling of depletion to the current thermobaric conditions and fluid saturation of the reservoir system was performed. The total mass of LHC in the core model (reservoir oil and retrograde condensate) was assessed which can be further used to calculate LHC recovery factors in experimental modelling of LHC recovery techniques at late stages of Vuktyl field development.
Control and regulation of downhole pumping equipment work characteristics, ensuring of industrial and ecological safety, reduction of oil shortage depends a long on control devices existing and well head measuring. Nowadays level of existing and well head setup needs development for oil shortage decreasing, operation safety, breakdowns and incidents exclusion.
This work presents a novel design of an open-type chain drive for a sucker-rod pumping unit with a 3.5-m length stroke and a 35 kN load capacity. This chain drive is mounted directly above the well head, and is an optimal solution for rod-lift production of low-volume wells. For the chain drive body, double tee profiles with parallel faces are used, which serve as both a support structure and balance weight guides. The paper presents technical characteristics of the new-design chain drive in comparison to PTs 30 model chain drive developed by the Bugulma Mechanical Plant, as well as a case study. The authors analyze technical solutions and consider ways to improve the chain drive design. It is recommended to reduce weight of the chain body, use a screw-pile foundation, and dismountable guides made of high-grade steel.
Materials and methods
GOST 26020-83 I-beam No. 55 with Parallel Flange Edges, cylindrical triple reduction gearbox 1TsZU-160-100-31-U1, 2.2-kW explosion-proof motor 4ВР90L4 with shaft speed of 1430 min-1, roller chain 1NP 50.8-145 with breaking strength of 263 kN, roller chains 1NP 31.75-192 with breaking strength 100 kN. Theoretical substantiation of technical characteristics and operational advantages, design and construction of test specimen, filed testing, analysis of test results.
A new chain drive was designed to enable lifting capacity of as high as 35 kN, stroke length of 3.5 m and oscillation frequency from 0.5 to 2.5 min-1. Field tests confi both serviceability of the drive and its compliance with specifi ation requirements. At the same time, some challenges during wellhead operations were revealed. These were associated with limited-access conditions within drive sub-frame.
Lessons learned from development, construction and fi d testing of PTs 35-3.5-0.5/2.5 chain drive test specimen brought forth further design improvements. Particularly, the housing of the drive may be implemented as an independent lightweight metal structure while replaceable, space-adjustable guideways may be made of mechanically upgraded steel to ensure high quality of the surface. Appropriate drive base plates are screw piles screwed into the ground up to fi soil level and below soil frost depth in winter.
As the reservoir fluid is extracted from the oil-bearing reservoir, the natural energy, under the action of which the fluid flows into the production wells, decreases and, as a result, the flow rates of production wells drop down. Currently, the newly commissioned oilfields in the Republic of Tatarstan and the Ural-Volga region are characterized by the presence of viscous oil and low reservoir pressure, as well as directionally drilled the wellbores. In this regard, the task of oil recovery enhancement, creating a way to intensify oil production under conditions of low reservoir pressure and high viscosity of the production becomes urgent. The article proposes a comprehensive method to develop a highly viscous oil fi d, comprising drilling a system of interconnected vertical and horizontal wells. Experience in creating a hydrodynamic connectivity in a fragment of an oil well system and the results of the steam-heat and chemical treatment of the bottom-hole zone of this fragment are also presented.
Currently, in the field of oil production, horizontal and controlled directional wells, as well as sidetracks, are widely used since they provide a large area of contact between the producing reservoir and the wellbore. The operation of such wells by serial borehole sucker rod pumps is limited by the maximum allowable angle of inclination of the sucker rod pump. Also a complicating factor in the exploitation of oil fields, in particular the Ural- Volga region, is the presence of high-viscosity oils. The article presents the operational experience of the developed differential pump units for controlled directional and horizontal wells in complicated conditions, including at slope angles higher than permissible for serial pumps. The installation is certified, its serial production is mastered, it is introduced on 12 wells.
For efficient development of oil fields, oil companies are forced to apply new technologies in their production and to search for highly efficient solutions optimizing the process of oil production. One of the directions of optimizing intensification in terms of hydrocarbon production technology is the technology of simultaneous-separate operation (WEM) of formations in one well. The use of experimental data allows us to show the effectiveness of the WEM in the development of Tournaisian, Visean and Vereisk-Bashkir sediments, but at the same time, further experimental work is needed to involve other developed horizons.
The combination of the conditions (stress- strain state and temperature) and rheology (creep) of rocks in certain horizons, especially for rock salts, leads to stress concentration during the construction and / or operation of wells, which leads to the destruction of the well design. Therefore, the selection and study of the rheological characteristics of rock salts from the East Siberian deposits should be put into practice. The paper presents the results of laboratory studies of rock salts in the context of one of the field in Eastern Siberia and the construction of an elastic- visco-plastic model for calculating the dependence of the creep pressure on the casing on time. According to the results obtained, recommendations are made for choosing a casing string at a given service life of the well design.
The paper describes the evolution of design decisions for the development of the gas-oil zone of AB1-5 reservoir, an assessment of the current fl type of the gas cap zone, the main assumptions and a strategy for further development of the gas-oil zone and the gas cap of the Samotlor Field.
The purpose of this work is to identify the interaction between the developed and undeveloped oil deposits in a multi-layer field, complicated by the fault causing hydrodynamic connection between the layers. The study is carried out through flow simulations for a hypothetical sector of a multi-layer oil field. The multivariate calculations carried out made it possible to conclude that the presence of a hydrodynamic connection through the fault between the developed deposit and the deposit left for later production can significantly influence production dynamics, and lead to changes in reserves, composition and properties of reservoir oil in the undeveloped deposit before putting it into production.
In modern conditions, the share of lowyield oil deposits with low-permeability reservoirs increases among the newly introduced fi ds. Such deposits, as a rule, are exploited with low bottomhole pressures in wells and worsened performance of pumping equipment due to the infl e of free gas. Reduction of the negative eff of free gas on the pump is achieved in various ways in each case. One of the optimal methods is the use of shanks with elongated intake fi ers. The paper describes a number of other technological and technical methods for reducing the harmful eff of free gas on the operation of pumping equipment.
Temperature signifi antly infl es the operation of submersible downhole equipment and can lead to failure due to overheating, salt and paraffi deposits on the equipment. To prevent complications, it is necessary to correctly predict and choose safe thermic modes. The article considers the model of heat exchange between the equipment and well nodes, which allows calculating the temperature and predicting the thermic mode of the well. The model can be used for selection, analysis and monitoring, in the algorithms of a switchboard.
A number of factors adversely aff the operation of the commercially available oil well pumping units, especially in wells with high viscosity production, which requires development of a high performance installation, in particular for such oil wells. The adverse eff of a part of these factors decreases with the increasing stroke length of the plunger. The stroke length of the previously designed installations ranges from one to hundreds of meters. Based on the conducted experiments, the optimal acceptable stroke length has been determined for the developed Long Stroke Deep Well Pumping Unit DGNU-2-2.5. where the traction element for the string of rods is a round-link chain, which is attached to a chainwheel performing bidirectional rotation. The designed equipment provides the following: smooth adjustment of the length and speed of the plunger's up and down movement in accordance with production capabilities of the well, remote monitoring, saving and changing of parameters, protection against exceeding the set parameters, etc. DGNU-2-2.5 unit is certifi its commercial manufacturing has been launched, and it has been implemented on 35 wells in various oilfi ds so far.
Operation of Iranian high-viscosity and heavy oil fields requires increasing the efficiency of production. Traditionally, waiting for the solution of this problem using thermal and chemical methods, the implementation of which is often a very costly undertaking. The article analyzes the method of polymer flooding as a technology to improve the efficiency of production of high viscosity and heavy oil fields in Iran.
The authors emphasize the fact that surface facilities projects often lack initial data even when this data is enough for a development project. The article substantiates the role of scientific research, including basic research, for reliable design of complex facilities.
This article presents a new approach to simulating thermal gas effects using the CMG STARS software. The essence of the proposed approach is the direct consideration of various hydrocarbonand organic complexes in the geological and hydrodynamic model. This approach allows taking into account the geochemical parameters obtained on the basis of core and geophysical studies, in addition, there is a significant decrease in the computation time.