DOI: 10.24412/2076-6785-2023-4-22-27
Abstract
To ensure consistent effect of the repeated selective MSHF technology, the geological and engineering criteria have been defined in this work and a decision-making algorithm for ranking and selecting well-candidates for repeated MSHF in horizontal wells has been developed. The algorithm is successfully applied to maintain the level of oil production in VK1-3 zones of the Kamenny Area of Krasnoleninsky Field covered by horizontal wells. At the end of 2022, pilot tests of the repeated selective MSHF technology in 12 horizontal wells were carried out. The EOR measures implemented in these wells have been recognized as successful both technologically and economically.
Materials and methods
Moreover, a tool for automated selection of well-candidates for repeated selective MS fracs in horizontal wells based on MS Excel (using the Visual Basic programming language) has been created and tested.
Keywords
repeated selective multistage hydraulic fracturing, horizontal well, candidate-well ranking algorithm, candidate-well selection criteria, automated candidate-well ranking tool
DOI: 10.24412/2076-6785-2023-4-16-21
Abstract
The article considers peculiarities and complications of killing gas wells in Achimov reservoirs (Ach3-4 and Ach5 2-3 formations of Novo-Urengoi and Vostochno-Urengoi license areas) using blocking compositions. The research has shown that suspension blocking compositions thickened with xanthan and starch are applicable for blocking of the bottom-hole zone in the presence of hydraulic fractures and withstand repression of no less than 14 MPa. The prospects of continuing research of blocking compositions thickened with surface active substances have been confirmed.
Materials and methods
Rationale for a new technology for killing with bottomhole zone blocking based on international experience and analysis of geological and technical conditions of the Novo-Urengoyskiy and Vostochno-Urengoyskiy license areas. Physical-chemical and filtration studies of high-density blocking compositions in the conditions of the object in question.
Keywords
Urengoyskoe field, well killing, gas wells, abnormally high reservoir pressure, high temperature, fluid loss, blocking compounds, suspensions, modification
DOI: 10.24412/2076-6785-2023-3-52-57
Abstract
The article deals with peculiarities and complications when killing gas wells in conditions of Achimovsky reservoirs (Ach3-4 and Ach52-3 formations of Novo-Urengoyskiy and Vostochno-Urengoyskiy license areas). In particular, there is intensive absorption of liquids, reduction of well productivity, corrosive effect on downhole equipment, and loss of stability in high temperature conditions. The dependence of the change in the skin factor on the density of the basic polymer-clay drilling mud used for killing the well has been determined. On the basis of the conducted complex of laboratory tests it was established that the modified high-density solutions on the basis of calcium chloride and calcium nitrate mixture (density 1 600 kg/m3) and zinc chloride and calcium bromide mixture (density 1 910 kg/m3) provide high recovery of formation model permeability after killing.
Materials and methods
Analysis of the results of application of killing technologies at the
Novo-Urengoyskiy and Vostochno-Urengoyskiy license areas. Substantiation of a choice of new technology on the basis of world experience and results of researches of basic applied fluids. Physical-chemical and filtration studies of high-density modified salt solutions in the conditions of the object in question.
Keywords
Urengoyskoe field, well killing, gas wells, abnormally high reservoir pressure, high temperature, fluid loss, blocking compounds, suspensions, modification
DOI: 10.24412/2076-6785-2023-2-63-66
Abstract
This article reviews the studies related to the permeability properties of core samples from terrigenous reservoirs when treated with a polymer-silicate concentrate (PSC): permeability values for water before and after the treatment have been determined, and the results of experimental works and tests have been presented. In the course of research we have obtained the residual resistance factor for water as a ratio of the initial permeability for water obtained before the reagent injection to its remaining value (after the treatment). The conclusions and guidelines for
the application of the PSC technology have been presented.
Materials and methods
Materials: a unit to determine the oil displacement factor and phase permeabilities on standard core samples under simulated reservoir conditions, core samples of terrigenous reservoirs, the PSC margin, samples of formation water and hydrochloric acid. Methods: removal of infiltrated water, evacuation, saturation with a saline water, determination of effective permeability for water, injection of PSC margins, determination of final permeability.
Keywords
terrigenous reservoirs, water flooding of oil-bearing formations, permeability properties, alteration (redistribution) of filtration flows, conformance control
DOI: 10.24412/2076-6785-2023-2-56-61
Abstract
Taking into account the accumulated knowledge regarding the choice of hydraulic fracturing fluids and their subsequent approbation within
the framework of pilot industrial and research works on the Turonian deposits of analogous deposits, an alternative hydraulic fracturing fluid was selected, the use of which will reduce the negative impact on productive formation (relative to fresh water), as well as to increase the environmental and economic component of the work as a whole in relation to hydrocarbon-based hydraulic fracturing fluid (diesel fuel).
Materials and methods
Based on an analytical review of the accumulated knowledge base regarding the choice of hydraulic fracturing fluid for the deposits of the Turonian stage (T) and carrying out our own laboratory tests of the core, recommendations were formed on the use of an alternative hydraulic fracturing fluid for the purposes of pilot work on the considered asset.
Keywords
turonian stage, hydraulic fracturing fluid, laboratory-based core analysis, linear expansion of clays
DOI: 10.24412/2076-6785-2023-2-51-54
Abstract
The development of hard-to-recover reserves with reservoir permeability less than 0,5 mD poses challenges for specialists to increase the profitability of oil production. The main direction of solving this problem is to increase productivity by drilling horizontal wells with a liner length of more than 1 000 m and performing multi-stage hydraulic fracturing. The design and implementation of promising designs of hydraulic fracturing fractures requires new approaches to assess their predictive productivity. Existing analytical and numerical methods for calculating predicted productivity use average fracture parameters. In practice, designs are often characterized by complex geometry and uneven distribution of conductivity in the volume of the hydraulic fracture. The use of incorrect algorithms for determining the average parameters of fractures leads to a significant deviation of the dynamics of the actual well flow rate from the calculated one. This leads to the use of non-optimal designs during hydraulic fracturing and a decrease in the profitability of extraction from hard-to-recover resources. To improve the quality of evaluation of hydraulic fracturing design efficiency, a technique for integrating a hydraulic fracturing simulator and a hydrodynamic simulator has been developed, which allows performing a correct calculation of well productivity.
Materials and methods
To solve the problem, the work proposes:
• designing perspective designs in hydraulic fracturing simulator;
• import of designed designs into hydrodynamic simulator;
• calculation of well productivity with designed hydraulic fractures in a hydrodynamic simulator;
• selection of an effective design for pilot testing and implementation.
Keywords
hard-to-recover reserves, hydrodynamic modeling, hydraulic fracturing, hydrodynamic simulator, hydraulic fracturing simulator
DOI: 10.24412/2076-6785-2023-2-44-47
Abstract
Offshore Arctic hydrocarbon fields’ development in the Russian Federation using subsea production systems is determined by a wide range of different factors.
It is proposed to consider the architecture of the field development as a 3D model with extended and concentrated objects, including wells, subsea completion of wells, pipelines and other elements of the subsea production systems.
The necessity and possibility of using optimization approaches for designing the architecture of a hydrocarbon deposit’ subsea development in arctic conditions is shown.
The practical implementation of the method for searching for the optimal architecture of the development of the Arctic field for the generalized case – “field with several deposits” is performed on the basis of a previously developed search algorithm on a 3D model for the optimal configuration of subsea production systems and wells between two points based on the Bellman-Ford optimality principle and the Lee algorithm.
Materials and methods
The experience of the Russian Federation in the optimal design of linearly extended objects and the analysis of arctic conditions. Existing methods of optimization of trunk pipelines.
Keywords
subsea production systems, optimization, development, Arctic
DOI: 10.24412/2076-6785-2023-2-38-42
Abstarct
The article presents the results of determining a more effective well construction for the area improved reservoir properties of zones in the ring structures of carbonate reservoir. This reservoir is characterized by low permeability and high compartmentalization. The stratum is actually developed by directional and horizontal wells. Based on the analysis of well efficiency the productivity of horizontal wells is higher the productivity of directional wells. In order to assess the development prospects, a full-scale reservoir simulation model (dynamic flow model) was created for prediction simulations. Based on the results of reservoir model simulation, it was found that the best method for drilling is the MLT.
The recommended design was implemented in the Osinsky horizon. The positive effect of drilling have been scaled to the Osinsky horizon.
Materials and methods
An analysis of the conducted seismic surveys was carried out,
the approach to identifying the ring structures of the patch reef zone was determined. Potentially productive zones for drilling in the area of ring structures have been identified. An assessment of various well design options was carried out using a reservoir simulation model (dynamic flow model).
Keywords
multilateral well, low permeability, carbonate reservoir, oil and gas field
DOI: 10.24412/2076-6785-2023-1-76-80
Abstract
The article considers the peculiarities of well killing in the conditions of terrigenous high-permeability reservoirs, typical for Eastern Siberia in the example of formation VCh 1–2 of Verkhnechonskoye oil-gas-condensate field are described. Studies of the instantaneous filtration composition for the purpose of controlling absorptions during well killing and field tests of the technology were carried out. The results testify to promising application of compositions with spurt lossfor killing wells in complicated conditions, exploiting terrigenous reservoirs of Eastern Siberia.
Materials and methods
Analysis of the application of killing technologies with bottom-hole zone blocking in the Verkhnechonsk oil and gas condensate field. Substantiation of a choice of the new technology on the basis of the world experience. Physico-chemical and filtration studies of the new composition in the conditions of the considered object. Analysis of the results of field testing of the considered technology on the well.
Keywords
well killing, abnormally low reservoir pressure, low temperature, fluid loss, blocking compounds, composition with spurt loss, Eastern Siberia
DOI: 10.24412/2076-6785-2023-1-72-75
Abstract
The migration of residual oil is partial flow of reserves that was displaced into zones with no production wells or from unswept zones after well shutting. This process is facilitated by favorable geological conditions, such as high continuity, permeability and connectivity of the formation, and the presence of anticlinal dome. Based on the results of drilled transit wells, the oil migration effect was confirmed, recommendations
for further development of shallow marine sandstone of one of the fields in Western Siberia were given.
Materials and methods
This paper presents an algorithm for oil field secondary development at a late stage of development, is proposed, which includes
the integration of research: selection and analysis of a new core, revision of the reservoir properties of rocks, conducting gyroscopic studies on old wells, analyzing the saturation of transit wells, rebuilding a hydrodynamic model with new data.
Keywords
oil migration, the last stage of oil field development, the development
of residual oil reserves
DOI: 10.24412/2076-6785-2023-1-66-69
Abstract
The article presents the example of searching for an analogue, the adaptation of the hydrodynamic model of the target reservoir on the history of the selected analogue development and searching optimal development option by carrying out multivariate calculations.
Materials and methods
Characteristics of displacement of an analogue reservoir object.
Using an analogue object to verify the hydrodynamic model of a new reservoir object.
Keywords
hydrodynamic model, development system, multivariate calculations, geological-physical characteristics, analogue, oil and gas condensate reservoir
DOI: 10.24412/2076-6785-2023-1-61-65
Àbstract
The article presents the experience of calculating the potential for reducing water production, developed as part of a project to reduce the cost of lifting well products. The idea of the work is to calculate the probability and volume of water production exceeding the level of current production of oil reserves. It is assumed that the positive difference between the actual and theoretical water cut calculated from the production of oil reserves in the well determines the potential for reducing water production and is associated with extraction from an inappropriate interval, or with a violation of the integrity of the well structure, or with water breakthroughs through highly permeable layers, or cone formation. The probability of extraction of “foreign water” is estimated by the degree of compliance with the signs of abnormal flooding.
Materials and methods
The article describes a methodology for analytical search of candidate wells for repair and insulation works based on the developed criteria. Geological and field data of monthly operational reports, data of technological modes, data on perforation intervals and information of design. The results of the calculations allow us to assess the economic efficiency of potential measures to reduce water production.
Keywords
squeeze job, water shut-off operations, casing patch operations, “foreign water”, productivity coefficient, water cut, premature watering
DOI: 10.24412/2076-6785-2023-1-56-60
Abstract
This article is devoted to the study of geomechanic and porosity clays properties influence on the processes of pressure redistribution and fluid filtration in the well drainage area, and as a result, on well productivity. Comparison of the calculation results showed a significant effect of clay interlayers in the reservoir section on the performance and productivity of the well.
Materials and methods
The study was carried out by creating synthetic hydrodynamic models with a different number of clay interlayers in the section of the productive formation, while maintaining the volume ratio between sandstone and clay in the ratio of 50:50. The Arps and Fetkovich methods were used to analyze decline curve anaysis production and calculate predicted values of cumulative production in the area of well drainage, assess and compare the rate of change in fluid production in wells.
Keywords
clay rocks, pore space compressibility, reservoir properties, reservoir modeling, decline curve analysis, Arps method, Fetkovich method
DOI: 10.24412/2076-6785-2023-1-46-53
Annotation
The paper considers an approach to the development of deposits of tight oil, characterized by a complex geological structure, ultra-low permeability (less than 1 mD) and saturation differentiation. The use of standard approaches and development technologies for such complex reservoirs makes it difficult to obtain high efficiency of oil recovery. In order to choose the optimal development technology, the applicability of gas methods
for enhanced oil recovery was evaluated using analytical techniques and calculations based on a compositional flow model.
Materials and Methods
The paper gives the numerical estimations of the Minimum Miscibility Pressure (MMP) of oil and various gas agents (APG, CO2, methane) made via correlations and EOS matched to standard studies
of downhole samples. A preliminary feasibility study of various development options for the reservoir in question (water and gas injection) was performed on a sector composite flow simulation model.
Keywords
tight oil, low permeability, hydraulic fracturing, pilot works, technology testing, gas methods of enhanced oil recovery
DOI: 10.24412/2076-6785-2023-1-41-45
Abstract
The work is devoted to the study of the effect of the hysteresis of relative permeability on the numerical evaluation of the effectiveness of water-alternating-gas (WAG) effects on models of various scales: a one-dimensional model of the core column (evaluation of the effect of the hysteresis of the core column on the quality of model adaptation to the results of flow experiments on core columns in the absence of gravity), a two-dimensional synthetic model of two wells (evaluation of the effect of hysteresis relative permeability for the amount of additional oil production in the presence of gravity), three-dimensional full-scale model of the deposit (evaluation of the effect of the hysteresis relative permeability on the efficiency of the WAG).
Materials and methods
Materials: results of core experiments on oil displacement by gas and water fringes. Methods: numerical simulation using the Eclipse 300 hydrodynamic simulator.
Keywords
hysteresis relative permeability, oil and gas miscibility, efficiently of WAG
DOI: 10.24412/2076-6785-2023-1-36-40
Abstract
Currently, in the Eastern Siberia oil fields, in the conditions of infrastructural restrictions, the simultaneously produced gas utilization problem, as well as breakthrough of gas caps extracted during the oil rims development, is acute. One of the ways to limit gas production during the oil rims development is the autonomous monitoring devices (AICD) usage at the completion of the well. At the Srednebotuobinskoye field, located in Eastern Siberia, successful work was carried out on the autonomous inflow control devices usage and full-scale replication began as part of the thin oil rim development of the Botuobin horizon.
Materials and methods
As part of the pilot project, 4 wells with AICD were implemented. Based on the results, full-scale replication has begun. For the completion design, a tool has been developed for arranging the amount of AICD
in each segment of the well, depending on the geological and technological conditions.
Keywords
autonomous inflow control device, AICD, cone formation, gas breakthrough, gas factor, accumulated oil production, Eastern Siberia, Botuobinsky horizon
DOI: 10.24412/2076-6785-2022-3-48-52
Abstract
An integrated approach has been formed to justify the designs of planned gas wells, taking into account the accumulated experience in the formation of a strategy and technology for the development of the turonian stage. A decision matrix has been created for choosing the optimal well completion method depending on saturation (pure gas and water gas zones) and reservoir properties (in particular Kh). An express assessment has been developed for choosing a well completion method for poorly explored and undrilled zones.
Materials and methods
By forming and performing many calculations on sector hydrodynamic models depending on saturation (pure gas and water gas zones) and reservoir properties (in particular Kh), individual well designs, the number of stages of hydraulic fracturing and tonnage proppant are recommended for each of the typical zones of the productive formation
according to the created decision matrix.
Keywords
turonian stage, reservoir saturation zones, reservoir conduction zones, sector hydrodynamic models, well completion methods
DOI: 10.24412/2076-6785-2022-2-60-64
Abstract
The increase in the share of hard-to-recover reserves makes it relevant to introduce physico-chemical methods of increasing oil recovery. Polymer flooding is a promising method. One of the factors influencing the success of this technology is the retention (adsorption) of the polymer in a porous medium. At a high value of adsorption, there is an intense loss of viscosity of the injected composition, colmatation of the downhole region of the formation is possible. It is necessary to select compositions characterized by acceptable retention values in the reservoir of a particular deposit. The article provides an example of the assessment of adsorption, including the influence of various factors on its magnitude.
Materials and methods
Laboratory tests were carried out according to the guidelines of the Institute “Hyprovostokneft” [14] and of the American Petroleum Institute [15]. All stages of preparation of reservoir models and fluids for research are based on OST 39-195-86 “Oil. Method for determining the oil displacement coefficient by water in laboratory conditions”.
Keywords
adsorption, concentration, polymer, temperature
DOI: 10.24412/2076-6785-2021-5-46-51
Abstract
In this work, we studied the effect of bimetallic catalysts formed in situ from mixtures of oil-soluble iron and cobalt precursors in the process of aquathermolysis of heavy oil from the Ashalchinsky field. Based on the results of determining the group composition (SARA analysis) and viscosity-temperature characteristics, an improvement in the composition and an increase in the mobility of oil under the action of steam and a bimetallic catalyst is shown. It was found that the catalyst intensifies the destructive processes of resinous compounds, provokes the enrichment of the destruction products of the latter in the saturated and aromatic fractions with high molecular weight n-alkanes and polycyclic hydrocarbons, respectively. It was revealed that the proposed catalyst of the optimal composition is a mixture of individual and mixed oxides and sulfides of iron and cobalt (ferrospinels). Catalyst can be used at the Ashalchinsky field of heavy oil in conditions close to reservoir conditions (200 °C, 10 bar), as a reagent providing an increase in the degree of oil recovery.
Materials and methods
Heavy oil of the Ashalchinsky field of the Republic of Tatarstan, SARAanalysis, viscometry, gas chromatography-mass spectrometry (GC-MS), catalyst active form, XRD.
Keywords
heavy oil, steam treatment, bimetallic catalyst, oil-soluble precursors, catalyst active form, in-situ upgrading, EOR
DOI: 10.24412/2076-6785-2021-5-42-44
Abstract
This article evaluates the study of the direction of spread of natural fracturing and predominant direction of propagation of cavernousness of the carbonate reservoir of the Podol-Kashiro-Vereiskian object of the Elnikovskoye oil field. The studies are based on the analysis of information on the sampled core, tracer studies, the FMI method and the mutual influence of production/injection wells. The study identified the main directions of natural fractures and vugginess. These parameters must be taken for well coverage, in particular, adjusting the location of production/injection wells in order to prevent anticipatory water invasion, as well as when selecting candidates for geological and technical measures to increase the
final oil recovery factor.
Materials and methods
Based on the analysis of practical material on optimizing the conditions of the fields being developed in the territory of the Udmurt Republic.
Keywords
natural fractures, natural vugginess, development, oil field, carbonate reservoir rock, geological and technical actions, interference of wells