Getting More with Less: Low-Viscosity Fluid Implementation for a Conventional Formation in Western Siberia, Russia

Author(s):  
Fedor Yurievich Leskin ◽  
Inna Aleksandrovna Sakhipova ◽  
Nikita Mikhailovich Zorkalt?ev ◽  
Alan Kazbekovich Dzutcev ◽  
Svetlana Rafailievna Pavlova ◽  
...  

Abstract Oil-saturated strata of Western Siberia fields are represented by laminated low-permeability sandstone separated by shale layers. Therefore, when designing hydraulic fractures, it is important to create longer propped fracture half-length and provide coverage of oil-saturated layers along the entire net height. Implementation of high-volume proppant fractures in combination with high-viscosity crosslinked fluids leads to excessive fracture height growth. In some cases it results in ineffective proppant distribution in the target layer and, moreover, to unwanted water production if the water contact or water bearing formation is close. To overcome these issues, it was proposed to use a novel hydraulic fracturing fluid that is a viscous slickwater based on synthetic polymer-polyacrylamide (also known as HiVis FR or HVFR). The low viscosity of HVFR (about 10 times lower than that of a crosslinked gel) allows a long fracture to be created and restricts height growth. Additionally, use of polyacrylamide instead of guar gives a larger value of retained conductivity. The full workflow for implementing HVFR for hydraulic fracturing in conventional formations includes candidate evaluation, HVFR laboratory testing, an integrated engineering approach to fracture modeling, operational considerations, and post-fracturing production analysis. The workflow evolved during the technology implementation cycle in a specific oil field, particularly the modeling step, which used a new high precision multiphysics (MP) model. The MP model provides an advanced, high-quality high- precision fracturing design to properly evaluate fracture geometry and proppant distribution by accounting for proppant settling in viscoelastic fluid and an accurate simulation of proppant placement when using a pulsing schedule. During the 2-year project, considerable success was achieved in expanding of the technology implementation scope. Several records were achieved on Kondinskoe oil field - a 150-t of ceramic proppant (SG, specific gravity,~3.1) were placed in a conventional reservoir by low-viscosity fracturing fluid and the first worldwide combination of viscous slickwater with channel fracturing technology was successfully performed. The use of HVFR, due to ability of fracture growth control, prevented breakthrough into the water-bearing zone. In addition, considerable improvement of operational efficiency was achieved due to use of cold water, lower amounts of additives, and less equipment, which resulted in a smaller location and environmental footprint. This first implementation of the viscous slickwater in conventional wells in Western Siberia enabled evaluating its effect on production rate. Increasing demand for maximizing production from low- permeability formations makes the result of this viscous slickwater implementation campaign of special interest. The application of a full engineering workflow, including design, execution, and evaluation of the Viscous slickwater treatments is a key to successful technology implementation and production optimization.

2014 ◽  
Vol 933 ◽  
pp. 202-205
Author(s):  
Bo Cai ◽  
Yun Hong Ding ◽  
Yong Jun Lu ◽  
Chun Ming He ◽  
Gui Fu Duan

Hydraulic fracturing was first used in the late 1940s and has become a common technique to enhance the production of low-permeability formations.Hydraulic fracturing treatments were pumped into permeable formations with permeable fluids. This means that as the fracturing fluid was being pumped into the formation, a certain proportion of this fluid will being lost into formation as fluid leak-off. Therefore, leak-off coefficient is the most leading parameters of fracturing fluids. The accurate understanding of leak-off coefficient of fracturing fluid is an important guidance to hydraulic fracturing industry design. In this paper, a new field method of leak-off coefficient real time analysis model was presented based on instantaneous shut-in pressure (ISIP). More than 100 wells were fractured using this method in oil field. The results show that average liquid rates of post-fracturing was 22m3/d which double improvement compared with the past treatment wells. It had an important role for hydraulic fracturing stimulation treatment design in low permeability reservoirs and was proven that the new model for hydraulic fracturing treatment is greatly improved.


2021 ◽  
Author(s):  
Mario Hadinata Prasetio ◽  
Hanny Anggraini ◽  
Hendro Tjahjono ◽  
Aditya Bintang Pramadana ◽  
Aulia Akbari ◽  
...  

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.


2021 ◽  
Author(s):  
Xinjun Mao ◽  
Chaofeng Chen ◽  
Renzhong Gan ◽  
Shubo Zhou ◽  
Zichao Wang ◽  
...  

Abstract The candidate wells are tight oil wells and most of the wells in the area have a low recovery rate of fracturing fluid after fracturing treatment. The lithology is glutenite with weak cementation and a high sensitivity tendency. This paper presents the process of sensitivity evaluation and fracturing fluid evaluation. Also, this paper introduces a customized and optimized clay control fracturing fluid wells in a highly sensitive reservoir. Per local national standard, traditional methods of swelling test (ST) and x-ray diffraction (XRD) were employed for qualitative formation cutting analysis. An innovative trial was then developed to evaluate cores quantitatively by water sensitivity. A clay stabilizer was then chosen to be used for the highly sensitive cores and regain permeability testing of the broken fracturing fluid was performed. Based on the analysis and evaluation, a customized treatment design was initiated for the hydraulic fracturing treatment. The qualitative evaluation showed the rock is highly water sensitive and the cores easily collapse because of weak cementation. No flow could be established during traditional core flow tests with brine. The newly developed method used kerosene as the working fluid to prevent the cores from contact with water or brine. The core flow tests resulted in a velocity sensitivity damage rate of 92%, which is considered as highly velocity sensitive. Accordingly, a special clay stabilizer was chosen to be used in the fracturing fluid and the permeability damage of the broken fracturing fluid is only 26.9%(Table 16). Field results have shown that the fracturing fluid recovery rate in treated wells is higher than the area average level and treated wells have significant oil production increase. The innovative clay control fracturing fluid and its field application reduces the influence of water and velocity sensitivity. The customized treatment with special clay stabilizer helps increase the recovery rate of fracturing fluid in reservoirs with severe clay stability and weak cementation issues.


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Chengli Zhang ◽  
Peng Wang ◽  
Guoliang Song

The clean fracturing fluid, thickening water, is a new technology product, which promotes the advantages of clean fracturing fluid to the greatest extent and makes up for the deficiency of clean fracturing fluid. And it is a supplement to the low permeability reservoir in fracturing research. In this paper, the study on property evaluation for the new multicomponent and recoverable thickening fracturing fluid system (2.2% octadecyl methyl dihydroxyethyl ammonium bromide (OHDAB) +1.4% dodecyl sulfonate sodium +1.8% potassium chloride and 1.6% organic acids) and guar gum fracturing fluid system (hydroxypropyl guar gum (HGG)) was done in these experiments. The proppant concentration (sand/liquid ratio) at static suspended sand is up to 30% when the apparent viscosity of thickening water is 60 mPa·s, which is equivalent to the sand-carrying capacity of guar gum at 120 mPa·s. When the dynamic sand ratio is 40%, the fracturing fluid is not layered, and the gel breaking property is excellent. Continuous shear at room temperature for 60 min showed almost no change in viscosity. The thickening fracturing fluid system has good temperature resistance performance in medium and low temperature formations. The fracture conductivity of thickening water is between 50.6 μm2·cm and 150.4 μm2·cm, and the fracture conductivity damage rate of thickening water is between 8.9% and 17.9%. The fracture conductivity conservation rate of thickening water is more than 80% closing up of fractures, which are superior to the guar gum fracturing fluid system. The new wells have been fractured by thickening water in A block of YC low permeability oil field. It shows that the new type thickening water fracturing system is suitable for A block and can be used in actual production. The actual production of A block shows that the damage of thickening fracturing fluid is low, and the long retention in reservoir will not cause great damage to reservoir.


2018 ◽  
Vol 69 (6) ◽  
pp. 1498-1500
Author(s):  
Lacramioara Olarasu ◽  
Maria Stoicescu ◽  
Ion Malureanu ◽  
Ion Onutu

In the oil industry, crude oil emulsions appear very frequently in almost all activities, starting with drilling and continuing with completion, production, transportation and processing. They are usually formed naturally or during oil production and their presence can have a strong impact on oil production and facilities. In this paper we addressed the problem of oil emulsions present in a reservoir with unfavorable flow properties. It is known that the presence of emulsions in a reservoir can influence both flow capacity and the quality of its crude oil, especially when they are associated with porous medium�s low values of permeability. Considering this, we have introduced a new procedure for selecting a special fluid of fracture. This fluid has two main roles: to create new flow paths from the reservoir rock to wells; to produce emulsion breaking of emulsified oil from pore of rocks. Best fracturing fluid performance was determined by laboratory tests. Selected fluid was then used to stimulate an oil well located on an oil field from Romania. In the final section of this paper,we are presenting a short analysis of the efficiency of the operation of hydraulic fracturing stimulation probe associated with the crude oil emulsion breaking process.


2021 ◽  
Vol 11 (4) ◽  
pp. 1761-1780
Author(s):  
Nianyin Li ◽  
Fei Chen ◽  
Jiajie Yu ◽  
Peihong Han ◽  
Jia Kang

AbstractHydraulic fracturing is an important technical means to improve the development effect of low-permeability oil and gas reservoirs. However, for low pressure, low-permeability, tight, and high-clay sandstone gas reservoirs, conventional propped fracturing can cause serious damage to the reservoir and restrict the fracturing effect. The pre-acid fracturing technology combines acid treatment technology with sand-fracturing technology. A pre-acid system that meets special performance requirements is injected before fracturing. The pre-acid reduces the formation fracture pressure and removes clay damage. During acid flowback, the fracturing fluid is promoted to break the gel, dissolve the fracturing fluid residue and polymer filter cake, clean the supporting cracks, and effectively improve the fracturing effect. This study analyzes the process principle and technical advantages of the pre-acid fracturing technology based on the laboratory evaluation of the fracturing damage mechanism of low-permeability tight gas reservoirs. To meet the performance requirements of low-permeability tight gas reservoirs and pre-acid fracturing technology, a set of polyhydrogen acid system with long-lasting slow reactivity, low damage, and low corrosion was developed and used as the pre-fracturing acid. The acid system is mainly composed of the main agent SA601 and the auxiliary agent SA701. Then, on the basis of laboratory experiments, this acid system is used as the fracturing pre-acid to evaluate the fracturing improvement effect. The results show that the fracturing fluid system can better dissolve the fracturing fluid filter cake and remove the fracturing fluid damage.


2016 ◽  
pp. 49-57
Author(s):  
V. R. Kalinin

The article considers the advantages and limitations of hydraulic fracturing fluid based on carboxymethyl cellulose determined as a result of laboratory studies. As a result of testing the studied fluid manufacturing features compared with similar fracturing fluids it was determined that the fluid of interest can be effectively used as a fluid for formation hydraulic fracturing especially in low permeability reservoirs. This fluid is widely available and has a low cost. It can easily replace the foreign analogues.


Author(s):  
Вадим Александрович Чемеков ◽  
Артем Маратович Шагиахметов

Сейчас, когда истощение базы углеводородного сырья происходит все быстрее, разработка залежей низкопроницаемых коллекторов требует дополнительных методов стандартных способов эксплуатации. Одним из методов добычи трудноизвлекаемых запасов является многостадийный гидроразрыв пласта, который позволяет существенно увеличить эффективность эксплуатации горизонтальных скважин. Now, when the depletion of the hydrocarbon base is faster, the development of low-permeability reservoirs requires additional methods of standard operating methods. One of the methods for extracting hard-to-recover reserves is multi-stage hydraulic fracturing, which can significantly increase the efficiency of horizontal wells.


1984 ◽  
Vol 24 (02) ◽  
pp. 141-152 ◽  
Author(s):  
A. Settari ◽  
H.S. Price

Abstract Computer-based numerical simulation can be used as a tool for analysis of fracturing treatments and prediction of postfracturing well performance. The physical problem studied involves fracture mechanics, fluid flow, and heat transfer both in the fracture and in the reservoir. The numerical model predicts fracture extension, length, and width; proppant transport and settlement; fracture closure; cleanup, and postfracturing performance under different producing conditions. The number of physical features that are customarily neglected in fracture designs have been incorporated in the present model. These include stress-sensitive reservoir properties, proper two-phase calculation of leakoff and cleanup, stress-dependent fracture permeability and temperature- and time-dependent fracturing fluid rheology. The utility and a priori predictive capability of the model is illustrated with two examples of fracturing jobs. The first example is a marginal gas well stimulated by a medium-size gelled-water fracturing job. The second example is a massive foam fracture in the Elmworth basin. In both cases, the simulator predicted results that are in good agreement with the observed productivity. Introduction Fracturing technology has been developing rapidly in recent years. Both the size and sophistication of field treatments have increased dramatically. The development of low-permeability gas reserves is especially dependent on successful and economical application of fracturing technology. The low-permeability gas sands often have permeability below 1 ud and discontinuous (lenticular) or dual porosity structure. A number of very large treatments have been performed with varied results. Compared with the rapid development of field technology, design and analysis of massive hydraulic fracturing (MHF) treatments have involved traditional methods based on correlations and crude approximations. Design methods used by service companies and industry concentrate on the prediction of fracture shape and proppant placement, and as such do not predict accurately deliverability after the fracturing job. Such methods cannot be used for design optimization, which must be based on accurate long-term production forecasts. In addition, the various aspects of the process are, of necessity, treated separately. Typically, fracture extension, leakoff, fracturing fluid heatup, and cleanup all are determined independently using simplifying assumptions about their mutual influence. The need for production-forecasting tools has been recognized by reservoir engineers who developed analytical and numerical techniques for predicting the deliverability of fractured wells. The most advanced approaches of this type involve conventional finite-difference reservoir simulation techniques and are used for optimization of treatment size. The common weakness of analyses of this type is that the fracture is treated as static and many of the variables controlling deliverability (such as fracture length, conductivity, propped length, and height) must be entered and are typically obtained by the design methods discussed previously. Also, the influence of the fracturing job on the reservoir (such as damage by the fluid) cannot be properly accounted for. The need for tools that would model the entire process in a more rigorous fashion is obvious. Most of the information on the fracturing operations in the field must be obtained indirectly, and production testing yields the basic and most important data. A meaningful tool for analysis of treatments must therefore correctly model the interaction between the fracturing operation and the postfracture behavior. This paper describes development and field application of a comprehensive simulator that treats in an integrated fashion all important aspects of the problem. The correctness of our approach has been confirmed by validation against field data, showing excellent agreement. Our model still simplifies treatment of fracture containment, and ongoing development is directed toward enhancements that will allow a priori optimization of treatments including containment. General Description of the Simulator Although the model is general and can be used in other applications, this paper addresses only those features of interest in fracturing treatments. The relevant geometry is shown in Fig. 1. The model simulates two-dimensional (2D), compressible, two-phase flow and heat transfer simultaneously with initiation and propagation of a vertical hydraulic fracture. Once the fracture exists, appropriate equations of two-phase flow and heat transfer in the fracture also are solved. SPEJ P. 141^


2013 ◽  
Vol 848 ◽  
pp. 92-95
Author(s):  
Hai Yong Zhang ◽  
Shun Li He ◽  
Dai Hong Gu ◽  
Guo Hua Luan ◽  
Cheng Quan Men ◽  
...  

Hydraulic fracturing is an effective measure to increase oil production for the development of low permeability reservoir. The selection of perforating parameters has a direct effect on the fracture expansion, formation fracture cracking pressure and even the implementation success of fracturing in that the fracturing processing fluid and artificial fracture all need to pass through the extension of perforation. In field application, the selection of perforating parameters is usually determined base on experience without combining with the actual data of the hydraulic fracturing wells. This work focuses on analyzing the influence of perforating parameters on the productivity of fractured well based on an established productivity prediction model through analytical method.Results show that, take a specific area of Changqing oil field for example, the perforation diameter has little effect on the productivity after fracturing, the other optimized perforating parameters are as follows: the perforation degree 30~40%, perforation density 8~12 perforation per meter, perforation depth 0.2~0.3m. The results are helpful to guide the optimization of perforating parameters in low permeability reservoir.


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