Physical Modeling of Colmatation Processes in the Near-Well Bottom Zone  of Sredne-Botuobinsky Field. Part 2. Simulation of Colmatation  of a Formation Porous Space by Oil Components

Borisov, G.K.; Ishmiyarov, E.R.; Politov, M.E.; Волошин, А. И.; Smolyanets, E.F.; Barbaev, I.G.; Aa, Nikiforov; Ivanov, Evgeny

doi:10.30713/0207-2351-2018-12-64-67

Cited by 3 publications

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“…Therefore, resulting from the injection of large volume of cold water, a decrease in reservoir temperature is observed (Muslimov et al 1968;Mingareev et al 1968;Mezzomo and Rabinovitz 2001;Rocha et al 2003). The problem of clogging the pore volume of the near-wellbore area with wax resulting from a decrease in temperature is described by Borisov et al (2018), Yusupova et al (2016). The flooding experiments are carried out by the authors, proved that a decrease in temperature leads to core permeability decrease due to the formation of wax crystals.…”

Section: Introductionmentioning

confidence: 99%

Formation damage induced by wax deposition: laboratory investigations and modeling

Sandyga

Struchkov

Рогачев

2020

J Petrol Explor Prod Technol

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There are oil fields, wherein favorable conditions for the formation damage induced by wax deposition are created during production. The damage can be expressed by a decrease in porosity and permeability and a reduction in the drainage area. There are only a few unconventional fields, and this makes them unique. To prevent this complication, it is necessary to control the field production. Assuming the presence of such problem, the conventional reserves may turn into difficult oil reserves whose production is problematic, which will compromise the project profitability. The key to the problem is associated with the experimental procedure and research conditions for investigation wax crystallization in oil, being the subject of this paper. The authors showed that the use of WAT measurement technique in an open measuring system is not enough to control wax deposition in the reservoir pore volume. Based on the results of the flooding technique and micro-computed tomography, a digital core, that allows to simulate fluid flow in the porous medium of the core before and after formation damage, has been created. The calculation of the change in the thermal field around the injection well over time, according to the extended Lauwerier's concept, has been carried out. WAT of a wax-bearing solution was measured by the rheology method using an open measuring system (plate-to-plate measuring system under atmospheric pressure), and the dependence of viscosity versus temperature was obtained during experimental studies. The temperature was decreased from 60 to 10 °C at a cooling rate of 1 °C/min. The experiment was carried out at atmospheric pressure and a shear rate of 5 s −1 . Also, filtration technique and micro-computed tomography were used. The dependence of the pressure gradient versus temperature and the pore throat diameter distribution functions for the initial core and core with organic scales were obtained. The flooding experiment was carried out at a constant flow rate of 0.5 cm 3 /min and confining pressure of 4.1 MPa. The temperature was decreased from 40 to 33 °C at a cooling rate of 1 °C/h. The inflection points on the curves viscosity versus temperature and pressure gradient versus temperature confirm the WAT. The results of the laboratory experiments showed that WAT, measured by the rheology method is 3-4 °C lower than WAT, measured by the flooding technique. The results of the micro-computed tomography showed that initial porosity decreased from 9.0 to 2.1% as a result of wax deposition. The pore throats with diameters from 20 to 70 μm are involved in the clogging with wax. The calculation results confirmed the possibility of cooling the near-wellbore area of injector to a temperature equal to WAT and the cold front movement to the producing wells. The production profiles calculated based on the models of porosity and permeability reduction, showed that wax deposition in the near-wellbore area can cause a significant decrease in the productivity index. An effective remediation technology for injection wells ...

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Section: Introductionmentioning

confidence: 99%

Formation damage induced by wax deposition: laboratory investigations and modeling

Sandyga

Struchkov

Рогачев

2020

J Petrol Explor Prod Technol

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Complex matrix treatment technologies selection and adaptation for the injection wells of the Republic of Tatarstan oilfields

et al. 2022

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Nowadays, oil fields on the territory of the Republic of Tatarstan are developed with application of systems for reservoir pressure maintenance, involving injection of large volumes of water into the formation. Efficiency of waterflooding depends on the quality of the injected agent, and, despite the use of various technologies of preparation and treatment of injected water, with the lapse of time critical matrix porosity and permeability inevitably decreases. In this work the main sources of injection wells critical matrix clogging are considered: mechanical impurities, oil products and scales formation, and the results of the component composition analysis of deposits from cluster pumping stations are given. Using the Oddo-Thomson methodology, it is revealed that injected water is prone to calcite and barite deposition at bottomhole conditions. Physicochemical and core-flooding study of several reagents for removing colmatants: acid compositions, hydrocarbon solvents and complexing agents were carried out and their optimal formulations were determined. The matrix treatment technology, including the sequential injection of compositions based on hydrochloric and mud acids, was substantiated. An algorithm for calculating the optimal reagent volume has been developed on the basis of research data on the mineralogical composition of mechanical impurities and ionic composition of injected water. Four types of matrix treatment technologies were determined for the conditions of injection wells at the Romashkinskoye oil field Devonian formation, taking into account the composition of colmatant, and acid treatment designs were developed.

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Acidizing Combined with Heat Generating System in Low-Temperature Dolomitized Wax Damaged Carbonates

Folomeev

Magadiev

Khatmullin

et al. 2020

Day 2 Tue, October 27, 2020

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The article demonstrates the results of experimental and field studies of the thermal foam-acid treatment technology with the use of water solutions of heat and gas generating system. The potential temperature of the heat-generating reaction upon mixing of agents was estimated in laboratory conditions and the physical and chemical properties of acid solutions were determined. A series of filtration experiments was conducted on treating dolomitized core samples with a basic hydrochloric acid solution.The constant of the rate of reaction between the basic acid solution and dolomitized carbonate rock was determined based on the experiment results. The article provides a brief analytical overview of world experience of the thermochemical treatment of the bottomhole area. The technology selected for the tests called thermo-foam-acid and implies the step-by-step injection of water heat and gas generating solutions with an addition of surfactants and an initiator into the bottomhole area. The heat-generating reaction is accompanied by the generation of a large amount of heat, gases and hot foamed acid. Heating melts high molecular weight oil compounds, washes oil sheen from rock surface and increases the speed of its dissolution with hydrochloric acid. This foam acts as a diverter for the next portion of active acid and prevents undesired stimulation of high-permeability interlayers and fractures. Surfactants in the acid solution increase its ability to penetrate pores and microfractures. The physical modeling of a thermal foam-acid treatment has been performed. Arlanskoe (Kashirskian-Podolskian deposits) and Nadezhdinskoe (Famennian stage) fields where carbonate formations are characterized by high and increased oil viscosity, low reservoir temperature, fractured and dolomitized reservoirs were selected as a site to perform field tests. Well operation at these formations is complicated by the precipitation of asphaltenes, resins and paraffins in the bottomhole area. Solution injection parameters were recorded during treatments based on this technology. The technological efficiency of this treatment was confirmed based on bottomhole pressure and temperature changes during injection operations. Technology efficiency was analyzed and the well flow rate was monitored based on the field test results. The main stages of this work are shown in Figure 1.Figure. 1Project stages

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Physical Modeling of Colmatation Processes in the Near-Well Bottom Zone of Sredne-Botuobinsky Field. Part 2. Simulation of Colmatation of a Formation Porous Space by Oil Components

Cited by 3 publications

References 0 publications

Formation damage induced by wax deposition: laboratory investigations and modeling

Formation damage induced by wax deposition: laboratory investigations and modeling

Complex matrix treatment technologies selection and adaptation for the injection wells of the Republic of Tatarstan oilfields

Acidizing Combined with Heat Generating System in Low-Temperature Dolomitized Wax Damaged Carbonates

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