scholarly journals Integrated modelling approach to oil recovery increase of Achimov formation

2021 ◽  
Vol 6 (3) ◽  
pp. 103-113
Author(s):  
Dmitriy I. Torba ◽  
Alexander V. Bochkarev ◽  
Yuriy V. Ovcharenko ◽  
Alexandra E. Glazyrina ◽  
Yuriy S. Berezovskiy ◽  
...  
Keyword(s):  
Hydraulic Fracturing ◽  
Oil Recovery ◽  
Integrated Modeling ◽  
Wellbore Stability ◽  
Integrated Modelling ◽  
Reservoir Modeling ◽  
Low Permeability ◽  
Horizontal Drilling ◽  
Innovative Strategy ◽  
Applied Approach

Background. Tight sand deposits development has always been a challenging process that frequently requires application of innovative approaches. Horizontal drilling in non-uniform lithology is frequently accompanied by circulation, wellbore stability losses and other complications. Hydraulic fracturing stimulation does not always result in productivity increase, which reduces profitability of development. Due to the incomplete understanding of geological and geomechanical specifics of Achimov deposits, — formations with complex heterogenous structure, low permeability, presence of low-amplitude structural dislocations, — the controlled use of features of formation is hindered and, in turn, makes it necessary to develop an innovative strategy of their surveillance and stimulation. Aim. In purpose to optimize an existing development strategy of Achimov deposits in Vingayakhinskoe oilfield, we have developed and applied an approach involving complex cross-segment modelling. At the same time, verification of hypothesis on possibility to identify and activate naturally fractured zones. Materials and methods. To form criteria for verification of hypothesis of fracture network generation in Achimov deposits, a 1D and 3D geomechanical models have been built in view of the applied approach, along with a model of natural fractures. Development of hydraulic fracturing designs, efficiency of which has been evaluated with respect to such reservoir modeling results as predicted production rate and cumulative production, have been the next step, performed for different geological and geomechanical conditions. Thus, the principal feature of applied approach is coupling between geomechanical modeling, complex multivariant hydraulic fracturing modeling and reservoir modeling with the target to maximize production. Results. The well stimulation strategy, selected based on the results of multivariate integrated modeling, was successfully implemented as part of the pilot high-flow hydraulic fracturing operation, which led to an almost twofold increase in the initial production rates of project wells versus off set wells. Conclusions. The obtained results of the work confirm that the developed integrated modeling approach can serve as a reliable basis for optimizing the development of heterogeneous and low-permeability formations such as Achimov deposits.

Success Story of Optimizing Hydraulic Fracturing Design at Alpha Low-Permeability Reservoir

2021 ◽  
Author(s):  
Mario Hadinata Prasetio ◽  
Hanny Anggraini ◽  
Hendro Tjahjono ◽  
Aditya Bintang Pramadana ◽  
Aulia Akbari ◽  
...  
Keyword(s):  
Hydraulic Fracturing ◽  
Oil Recovery ◽  
History Matching ◽  
Initial Period ◽  
Earth Model ◽  
Low Permeability ◽  
Stress Profile ◽  
Reservoir Pressure ◽  
Fracturing Fluid ◽  
Fracture Closure

Abstract This paper describes the evolution of the hydraulic fracturing approach and design in the Alpha reservoir over the past years. Alpha reservoir in XYZ field is a laminated sandstone reservoir with low permeability in the range of 20 to 140 md at a depth of approximately 4,000 to 4,500 ft true vertical depth (TVD). XYZ field is located in Rokan block, Riau, Central Sumatra region. Due to Alpha reservoir's nature, producing from this reservoir commercially requires stimulation. Hydraulic fracturing has been applied as the selected stimulation method to increase productivity from this reservoir. However, several challenges were recognized during the initial period, such as depleted reservoir pressure, indication of fracture height growth, and low to medium Young's modulus, which leads to few screened-out cases as well as low production gain after the fracturing treatment. The fracturing job in Alpha reservoir has been applied since 2002. However, pressure depletion was observed through this time until waterflood optimization started in May 2018 by converting commingled injection to injection dedicated to the Alpha reservoir. The pressure responded and increased from 350 psi to approximately 800 psi. Hence this reservoir still cannot be produced in single completion without the hydraulic fracturing job due to laminated reservoir and low-permeability character. A detailed look at the mechanical earth model (MEM) was done to revise the elastic properties and stress profile considering reservoir pressure change. The revised model was later used as an input for fracture geometry simulation. Calibration injection tests were performed and analyzed prior to the main fracturing treatments to determine fracture closure pressure and leakoff characteristics, which led to fracturing fluid efficiency. Results of these tests were used in job modifications regarding pad percentage, fracturing fluid rheology, proppant volume, and proppant concentration. Pressure history matching both after fracturing and in real time as well as the temperature log were used to validate the MEM and fracture geometries. Each change, approach, and impact were documented and statistically analyzed to determine a generic trend and design envelope for the Alpha reservoir. Between 2019 and 2020, nine wells were stimulated that specifically targeted the Alpha reservoir, with continuous improvement in fracturing design and geomechanics properties with each well. After fracturing, the 30-day oil recovery was superior, higher than previous fractured wells, reaching more than 255 BFPD on average. The successful development of the Alpha reservoir with hydraulic fracturing led to further milestones to maximize oil recovery in XYZ field.

scholarly journals The efficiency of gas injection into low-permeability multilayer hydrocarbon reservoirs

2021 ◽  
Vol 3 (10) ◽  
pp. 100-108
Author(s):  
Sudad H AL-Obaidi ◽  
Miel Hofmann ◽  
Falah H. Khalaf ◽  
Hiba H. Alwan
Keyword(s):  
Hydraulic Fracturing ◽  
Oil Recovery ◽  
Gas Injection ◽  
Oil Production ◽  
Recovery Factor ◽  
Low Permeability ◽  
Compositional Model ◽  
Multistage Hydraulic Fracturing ◽  
Low Permeability Reservoirs ◽  
Working Agent

The efficiency of gas injection for developing terrigenous deposits within a multilayer producing object is investigated in this article. According to the results of measurements of the 3D hydrodynamic compositional model, an assessment of the oil recovery factor was made. In the studied conditions, re-injection of the associated gas was found to be the most technologically efficient working agent. The factors contributing to the inefficacy of traditional methods of stimulating oil production such as multistage hydraulic fracturing when used to develop low-permeability reservoirs have been analyzed. The factors contributing to the inefficiency of traditional oil-production stimulation methods, such as multistage hydraulic fracturing, have been analysed when they are applied to low-permeability reservoirs. The use of a gas of various compositions is found to be more effective as a working agent for reservoirs with permeability less than 0.005 µm2. Ultimately, the selection of an agent for injection into the reservoir should be driven by the criteria that allow assessing the applicability of the method under specific geological and physical conditions. In multilayer production objects, gas injection efficiency is influenced by a number of factors, in addition to displacement, including the ratio of gas volumes, the degree to which pressure is maintained in each reservoir, as well as how the well is operated. With the increase in production rate from 60 to 90 m3 / day during the re-injection of produced hydrocarbon gas, this study found that the oil recovery factor increased from 0.190 to 0.229. The further increase in flow rate to 150 m3 / day, however, led to a faster gas breakthrough, a decrease in the amount of oil produced, and a decrease in the oil recovery factor to 0.19 Based on the results of the research, methods for stimulating the formation of low-permeability reservoirs were ranked based on their efficacy.

PLANNING AND DRILLING OF SINUOUS HORIZONTAL WELLS FOR THE GRIFFIN AREA DEVELOPMENT

1994 ◽  
Vol 34 (1) ◽  
pp. 19
Author(s):  
D. Berean ◽  
T. Slate ◽  
T. Wallace ◽  
R. Aldred ◽  
L. Hedger ◽  
...  
Keyword(s):  
Oil Recovery ◽  
Vertical Section ◽  
Horizontal Wells ◽  
Wellbore Stability ◽  
Production Performance ◽  
Drilling Fluids ◽  
Planning Period ◽  
Horizontal Drilling ◽  
Formation Evaluation ◽  
Area Development

The Griffin Area Development in the Barrow Sub-basin of Western Australia consists of three major oil fields, the Griffin, Scindian and Chinook fields.One of many new concepts of subsea technology used for the Griffin Area Development is the application of horizontal wells with a sinuous profile to improve oil recovery in the Birdrong reservoir.Reservoir simulation modelling initiated the concept and as a result, a multi-disciplined team was formed early in the pre-development phase to plan and implement a horizontal drilling program. Issues which were addressed by this team during planning included wellbore stability, drilling fluids, liner and completion design, wellpath orientation, reservoir constraints and formation evaluation techniques.After an extensive planning period, three sinuous path horizontal wells, Griffin-5(H), Griffin-6/ST1(H) and Scindian-2/STI(H) were successfully drilled in early 1993 by a semi-submersible rig as part of the Griffin/Scindian fields development drilling program.These sinuous wells have a well path profile which intersects the reservoir in three low-angle passes of the vertical section over a horizontal length of between 800 and 950 m, in the shape of a sine wave.A feature of the wells was the use of geosteering techniques to keep the sinuous profile on track to intersect specific reservoir targets, using the latest in formation evaluation measurement while drilling (FEMWD) technology.Although technically successful, the economic benefit of the horizontal wells will be measured by their production performance when tied into the 'Griffin Venture' floating production facility, expected on stream in early 1994.

Design of Horizontal Wellbore in Dadas Shales of Turkey by Considering Wellbore Stability and Reservoir Geomechanics

2021 ◽  
Author(s):  
Sukru Merey ◽  
Can Polat ◽  
Tuna Eren
Keyword(s):  
Hydraulic Fracturing ◽  
Horizontal Well ◽  
Oil And Gas ◽  
Horizontal Wells ◽  
Horizontal Stress ◽  
Wellbore Stability ◽  
Horizontal Drilling ◽  
Horizontal Wellbore ◽  
Reservoir Geomechanics ◽  
Maximum Horizontal Stress

Abstract Currently, many horizontal wells are being drilled in Dadas shales of Turkey. Dadas shales have both oil (mostly) and gas potentials. Thus, hydraulic fracturing operations are being held to mobilize hydrocarbons. Up to 1000 m length horizontal wells are drilled for this purpose. However, there is not any study analyzing wellbore stability and reservoir geomechanics in the conditions of Dadas shales. In this study, the directions of horizontal wells, wellbore stability and reservoir geomechanics of Dadas shales were designed by using well log data. In this study, the python code developed by using Kirsch equations was developed. With this python code, it is possible to estimate unconfined compressive strength in along wellbore at different deviations. By analyzing caliper log, density and porosity logs of Dadas shales, vertical stress of Dadas shales was estimated and stress polygon for these shale was prepared in this study. Then, optimum direction of horizontal well was suggested to avoid any wellbore stability problems. According to the results of this study, high stresses are seen in horizontal directions. In this study, it was found that the maximum horizontal stress in almost the direction of North-South. The results of this study revealed that direction of maximum horizontal stress and horizontal well direction fluid affect the wellbore stability significantly. Thus, in this study, better horizontal well design was made for Dadas shales. Currently, Dadas shales are popular in Turkey because of its oil and gas potential so horizontal drilling and hydraulic fracturing operations are being held. However, in literature, there is no study about horizontal wellbore designs for Dadas shales. This study will be novel and provide information about the horizontal drilling design of Dadas shales.

The Development Method of Low-Permeability and Ultra-Low-Permeability Reservoirs by Waterflooding

2021 ◽  
Author(s):  
Azat Albertovich Gimazov ◽  
Ildar Shamilevich Bazyrov
Keyword(s):  
Hydraulic Fracturing ◽  
Oil Recovery ◽  
Horizontal Wells ◽  
Hydrodynamic Modeling ◽  
Low Permeability ◽  
Production Well ◽  
Development Method ◽  
Multi Stage ◽  
Horizontal Part ◽  
Low Permeability Reservoirs

Abstract The article describes a method for developing low-permeability reservoirs using horizontal wells with multi-stage hydraulic fracturing. The effectiveness of the new method lies in protecting the horizontal part of the production well by drilling it through a non-reservoir plastic reservoir adjacent directly to the target reservoir. The paper considers various implementations of the technology and estimates the increase in oil recovery factor for each of them based on the results of hydrodynamic modeling. The risks associated with the implementation of the technology are considered. Methods for their reduction are proposed.

scholarly journals Results of the development system optimization and increasing the efficiency of carbonate reserves extraction of the turney stage of the Chetyrmansky deposit

2021 ◽  
pp. 131-142
Author(s):  
T. R. Khisamiev ◽  
◽  
I. R. Bashirov ◽  
V. Sh. Mukhametshin ◽  
L. S. Kuleshova ◽  
...  
Keyword(s):  
Hydraulic Fracturing ◽  
Oil Recovery ◽  
High Efficiency ◽  
Methodological Approach ◽  
Horizontal Wells ◽  
System Optimization ◽  
Horizontal Drilling ◽  
Development System ◽  
Multi Stage ◽  
Carbonate Deposits

The article is devoted to the issue of optimizing the development system and increasing the efficiency of carbonate deposits of the Tournaisian stage of the Chetyrmanskoye field developing, and the formation of a strategy for their additional development. As a result of the horizontal drilling, the rate of withdrawal from current recoverable reserves in the main area in terms of reserves increased from 0.3 to 5%, which confirms the high efficiency of horizontal wells drilling with multi-stage hydraulic fracturing in reservoirs with high stratification and heterogeneity degree of the productive section in order to increase the rate of reserves production and achieve the approved oil recovery factor, as well as the high efficiency of the proposed methodological approach in the design of the facility development by a system of horizontal wells, the correct choice of the facility development strategy in the design solutions formation. Keywords: oil fields development; carbonate deposits; development of reserves; multi-stage hydraulic fracturing; horizontal well.

scholarly journals SHALE AS HYDROCARBON RESERVOIRS

2018 ◽  
Vol 39 (2) ◽  
pp. 71-75
Author(s):  
Adi Junira ◽  
Andy Setyo Wibowo
Keyword(s):  
Hydraulic Fracturing ◽  
Liquid Flow ◽  
Oil Shale ◽  
Hydrocarbon Exploration ◽  
Low Permeability ◽  
Horizontal Drilling ◽  
Main Obstacle ◽  
The Past ◽  
Shale Reservoir ◽  
Low Permeability Reservoirs

Nowadays, shale plays a role as hydrocarbon producing rock. Due to its unusual properties as a reservoir, shale is classified as an unconventional reservoir. Among these properties are the relatively low permeability (0.1 mD or less) and the relatively low porosity (10% or less). The relatively low permeability had been the main obstacle to extracting the hydrocarbon held by shale in the past. Nevertheless, the technologies of horizontal drilling and hydraulic fracturing have proven to be effective in stimulating a liquid flow in low permeability reservoirs such as a shale layer which has encouraged the hydrocarbon exploration in the oil shale industry. This paper is intended to provide an overview of technologies implemented in the current oil shale reservoir along with their challenges summarized from available sources in a concise manner.

4D Geomechanical Research for Fracturing Optimization of Low-Permeability Reservoir

2022 ◽  
Author(s):  
Sheng Zheng ◽  
Wei Zhou ◽  
Xiaoguang Wang ◽  
Liang Chen ◽  
Dan Xie ◽  
...  
Keyword(s):  
Stress Field ◽  
Hydraulic Fracturing ◽  
Oil And Gas ◽  
Production Capacity ◽  
Oil Field ◽  
Wellbore Stability ◽  
Low Permeability ◽  
Reservoir Stimulation ◽  
Single Well ◽  
Low Permeability Reservoirs

Abstract China has abundant low-permeability oil and gas resources. A lot of practice has proved that low-permeability reservoirs must undergo hydraulic fracturing to obtain commercial production capacity. Geomechanical characteristics are the key factor for fracturing. It plays a very important role in the oil field exploration and production. It is not only the driving force for oil and gas migration, but also provides a basis for wellbore stability analysis and drilling optimization design. The state of the formation stress field and the mechanical properties of the rock jointly determine the direction, shape and orientation of the fracture extension of the fracturing. Together it affects the stimulation effect of fracturing. Realizing the high-efficiency development of low-permeability reservoirs is a key and difficult problem facing for oil filed operator. Horizontal wells drilling and hydraulic fracturing are the core technology for increasing single well production in low-permeability reservoirs. The effectiveness of reservoir reconstruction directly determines the production capacity of the reservoir. In order to clarify the influence of static and dynamic geomechanics on the scale of reservoir stimulation in the process of horizontal well fracturing, and ultimately provide effective technical support for the formulation and optimization of reservoir stimulation design. This study is based on the study of single well one-dimensional geomechanics, using the structural characteristics and seismic attributes of low-permeability reservoirs to study the characteristics of the three-dimensional spatial distribution of mechanics. On this basis, combined with real-time fracturing treatment data and micro-seismic monitoring data, dynamic (four-dimensional) stress field simulations are continuously carried out. The research results can be mainly used to guide the optimization of reservoir stimulation and the evaluation of filed development plan.

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