Fracturing Experience of Tyumenskaya and Vikulovskaya Formations: Application of Novel Low-Viscosity Fracturing Fluids as an Alternative to Guar-Based Fluids

2021 ◽  
Author(s):  
Konstantin Yurievich Loskutov ◽  
Almaz Albertovich Sadretdinov ◽  
Michael Ivanovich Samoilov ◽  
Dmitriy Vasilevich Emelyanov ◽  
Yuri Aleksandrovich Delyanov ◽  
...  

Abstract Tyumenskaya and Vikulovskya stratas are the major development objects for Rosneft subsidiary – RN- Nyaganneftegaz, characterized by close location of target zones to other layers, breakthrough in which is not desirable. Thus, target zones of Tyumenskaya group of formations are located close to Abalakskaya strata, and Vikulovskaya group of formations is described by close location of the target hydraulic fracturing intervals to the water-saturated layers. Risks of multi-stage hydraulic fracturing are high due to the use of synthetic geological and geomechanical models and synthetic logging associated with different sections of horizontal wells. The article presents the implementation experience of specifically developed technological solution in order to increase profitability of development and production of hydrocarbons and decrease the risks of ineffective stimulation: use of low-viscosity viscoelastic hydraulic fracturing fluids based on synthetic polymer- polyacrylamide with inherited ability to control fracture height growth without a need in significant reduction of proppant volume. The work performed on development and introduction of novel low-viscosity fluids based on polyacrylamide on Vikulovskaya and Tyumenskaya formations - RN-Nyaganneftegaz development objects has become a new stage in the history of hydraulic fracturing of these formations, and as well as for other oilfields with similar geological structure and field development conditions. The gained experience formed a basis for the effective implementation of similar hydraulic fracturing fluid systems and increasing of well productivity following in the result of well stimulation.

Lithosphere ◽  
2021 ◽  
Vol 2021 (Special 1) ◽  
Author(s):  
Xin Cai ◽  
Wei Liu

Abstract Hydraulic fracturing experiments with low-viscosity fluids, such as supercritical CO2, demonstrate the formation of complex fracture networks spread throughout the rocks. To study the influence of viscosity of the fracturing fluids on hydraulic fracture propagation, a hydromechanical-coupled cohesive zone model is proposed for the simulation of mechanical response of rock grains boundary separation. This simulation methodology considers the synergistic effects of unsteady flow in fracture and rock grain deformation induced by hydraulic pressure. The simulation results indicate a tendency of complex fracture propagation with more branches as the viscosity of fracturing fluids decrease, which is in accord with experimental results. The low-viscosity fluid can flow into the microfractures with extremely small aperture and create more shear failed fracture. This study confirms the possibility of effective well stimulations by hydraulic fracturing with low-viscosity fluids.


2021 ◽  
Author(s):  
Mikhail Ivanovich Samoilov ◽  
Vladimir Nikolaevich Astafyev ◽  
Evgeny Faritovich Musin

Abstract The paper describes a system of approaches to the design and engineering support of multistage hydraulic fracturing: A method of developing multiple-option modular design of multistage hydraulic fracturing which is a tool for operational decision-making in the process of hydraulic fracturing.Building a Hydraulic Fracturing Designs Matrix when optimizing field development plans. The result was used to build decision maps for finding well completion methods and selecting a baseline hydraulic fracturing design. The paper also describes how the systematization of approaches, methodological developments, and decision templates can help in optimizing field development by drilling directional and horizontal wells followed by multi-stage hydraulic fracturing. The sequence of events and tasks that led to the development of the methodology, as well as its potential, is briefly described. The methodologies were developed during the execution of a hydraulic fracturing project at JK 29 reservoirs of the Tyumen Suite of Em-Yogovskoye field, after which they were applied in a number of other projects for the development of hard-to-recover hydrocarbon reserves in West Siberia.


2021 ◽  
Author(s):  
Ayomikun Bello

Abstract Slick water fracturing fluids with high viscosity and minimal friction pressure losses are commonly employed in hydraulic fracturing nowadays. At the same time, high injection rates can be used to perform hydraulic fracturing to get the calculated fracture sizes. The conventional algorithm for conducting a standard proppant hydraulic fracturing includes performing a pressure test using a linear gel without a trial proppant pack to determine the quality of communication with the formation and the initial parameters of the fracture; and performing a mini-hydraulic fracturing on a cross-linked gel with a trial proppant pack (1000 - 2000 kg) to assess the parameters of the fracture development used to correct the design of the main hydraulic fracturing operation. However, in complex geological conditions associated with the presence of small clay barriers between the target formation and above or below the water-saturated layers, as well as in low-productive formations, this conventional method of conducting hydraulic fracturing operations using high-viscosity fluids is not always suitable. Hydraulic fracturing in thin-layer formations is associated with a significant risk of the tightness established by the fracture being broken, as well as fluids contained in the underlying or overlying layers being involved in the drainage process. Hydraulic fracturing in low-productive formations creates fractures that are similar in shape to radial fractures, reducing the efficiency and profitability of the impact due to inefficient use of materials and reagents. The main task in this situation is to limit the height of the fracture development and increase their length. It is necessary to use low-viscosity fracturing fluids with a high ability to transfer proppants to reduce the specific pressure in the fracture and control the height of the rupture. The goal of this research is to develop such fluid.


2015 ◽  
Author(s):  
Dimitry Chuprakov ◽  
Romain Prioul

Abstract Weak formation bedding planes create a unique mechanism for hydraulic fracture height containment. They arrest the vertical growth of hydraulic fracture. The propagation across them may or may not occur. To quantify this fracture behavior, first we developed an analytical model of the elastic T-shaped fracture contact with frictional and cohesional interfaces. The model evaluates the fracture blunting and the shear activation of the interfaces. It predicts the buildup of the net pressure necessary for the fracture to cross the given interface. Next we conduct numerical simulations of the 3D fracture propagation in a formation with closely spaced horizontal interfaces. These simulations manifest intermittent and decelerated fracture growth in height, especially with low-viscosity fracturing fluids. This mechanism of fracture height containment is independent of the multilayer stress-contrast mechanism used conventionally. Combined with the stress mechanism, the fracture height containment model could alleviate the problem of height growth overestimation in some fracturing simulation cases.


2019 ◽  
Vol 16 (11) ◽  
pp. 4584-4588
Author(s):  
I. A. Pogrebnaya ◽  
S. V. Mikhailova

The work is devoted to identifying the most relevant geological and technical measures carried out in Severo-Ostrovnoe field from the period of its development to the present. Every year dozens of geotechnical jobs (GJ) are carried out at each oil field-works carried out at wells to regulate the development of fields and maintain target levels of oil production. Today, there are two production facilities in the development of the Severo-Ostrovnoe field: UV1a1 and BV5. With the help of geotechnical jobs, oil-producing enterprises ensure the fulfillment of project indicators of field development (Mikhailov, N.N., 1992. Residual Oil Saturation of Reservoirs Under Development. Moscow, Nedra. p.270; Good, N.S., 1970. Study of the Physical Properties of Porous Media. Moscow, Nedra. p.208). In total, during the development of the Severo-Ostrovnoe field, 76 measures were taken to intensify oil production and enhance oil recovery. 12 horizontal wells were drilled (HW with multistage fracking (MSF)), 46 hydraulic fracturing operations were performed, 12 hydraulic fracturing operations were performed at the time of withdrawal from drilling (HW with MSF), five sidetracks were cut; eight physic-chemical BHT at production wells; five optimization of well operation modes. The paper analyzes the performed geological and technical measures at the facilities: UV1a1∦BV5 of the Severo-Ostrovnoe field. Four types of geological and technical measures were investigated: hydraulic fracturing, drilling of sidetracks with hydraulic fracturing, drilling of horizontal wells with multi-stage hydraulic fracturing, and physic-chemical optimization of the bottom-hole formation zone. It was revealed that two geotechnical jobs, namely, formation hydraulic fracturing (FHF) and drilling of lateral shafts in the Severo-Ostrovnoe field are the most highly effective methods for intensifying reservoir development and increasing oil recovery. SXL was conducted at 5 wells. The average oil production rate is 26.6 tons per day, which is the best indicator. Before this event, the production rate of the well was 2.1 tons per day. Currently, the effect of ongoing activities continues.


2021 ◽  
pp. 49-59
Author(s):  
S. F. Mulyavin ◽  
R. A. Neschadimov

The oil field X belongs to the category of large in terms of initial recoverable reserves, multi-layer and complex in geological structure. The US1 object accounts for 20,3 % of the initial recoverable reserves, while the selection from the initial recoverable reserves is only 11,4 %, this makes object the most promising from the point of planning further development of the field. The analysis presented in the article is aimed at identifying problems and features of the development. During the analysis, we noted low reservoir properties of the object, high watercut of the produced products, the deterioration of the energy state of the deposits, which manifests itself in the form of a decrease in dynamic levels and a decrease in fluid flow rate. Drilling of wells, both production and injection, was carried out using hydraulic fracturing technology. Given the fact that the deposits of the US1 object are closed, lithological shielded and are characterized by the absence of an oil-water zone, the watering of wells, according to the our opinion, is associated with pulling up water from the underlying water-saturated formation as a result of the propagation of cracks obtained during hydraulic fracturing. The reason for the deterioration of the energy state is the commissioning of injection wells using hydraulic fracturing and the withdrawal of water through hydraulic fracture in the underlying formation.


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