scholarly journals • THE INFLUENCE OF CARBONIC ACID AMMONIUM SALTS ON THE FILTRATION PROPERTIES OF BOTTOM-HOLE FORMATION ZONE

Author(s):  
V. I. Dmytrenko ◽  
I. H. Zezekalo

The possibility of using ammonium carbonates to increase hydrocarbons extraction is considered. To study the effect of ammonium carbonate salts on the reservoir filtration properties a complex of experimental studies has been carried out. It has been established that carbon dioxide ammonium salts, in the absence of calcium chloride water, interact with carbonate rocks, increase the absolute permeability of reservoirs. The solutions of ammonium carbonate salts interact with calcium chloride type of formation water and form chemically precipitated chalk in the pores of the rock. Herewith the permeability of carbonate rocks decreases. The industrial tests of ammonium carbonate salts have shown an increase in gas flow rate by 30-50% at wells № 23 of Opishnyanske, № 115 of Mashivske, № 3 of Tymofiyivske gas condensate fields. The effect of the ammonium carbonates treatment of the formation is stipulated by the purification of the bottom-hole formation zone and an increase of the absolute permeability of the reservoirs. The increase of the condensation factor by 22-35% has been observed in wells № 56, 108 of Yablunivske and № 58 of Tymofiyivske gas condensate fields. The efficiency of the treatment is related to the simultaneous purification of the bottom-hole zone from asphalt-resinous contaminants and to the absolute permeability increase, as well as to the pore space hydrophilization and the increase in the mobility of condensate that has fallen due to the influence of carbon dioxide which generates as a result of the decomposition of carbonic acid ammonium salts. Thus, pilot tests at Opishnyanske, Mashivske, Tymofiyivske, Yablunsvske gas condensate fields of Poltava region confirmed the effectiveness of using ammonium carbonate salts to increase hydrocarbon production. The prospect of further research is aimed at developing a technology for increasing the liquid hydrocarbons production by the use of ammonium carbonate salts.

2015 ◽  
Vol 770 ◽  
pp. 349-353 ◽  
Author(s):  
O.V. Tailakov ◽  
E.A. Utkaev ◽  
D.N. Zastrelov ◽  
S.V. Sokolov

The paper displays the description of the method to assess coal seam filtration properties in a bottom-hole zone by physical imitation and use of equivalent materials. The evaluation function of permeability and filtration properties change in a bottom-hole zone was specified under conditions of Taldinskiy coal deposit in Kuzbass.


2021 ◽  
Vol 280 ◽  
pp. 07011
Author(s):  
Viktoriia Dmytrenko ◽  
Ivan Zezekalо ◽  
Yuriy Vynnykov ◽  
Nikolay Hristov ◽  
Gergana Meracheva

The work is devoted to the problem of increasing gas condensate production in gas condensate fields. It was found that ammonium carbonate salts, in the absence of calcium chloride type waters, interact with carbonate rocks, increase the permeability of reservoirs. Solutions of ammonium carbonate salts when interacting with formation water of the calcium chloride type form chemically precipitated chalk in the pore space, while the permeability of carbonate rocks decreases. A set of experimental studies was carried out to study the displacing and washing properties of ammonium carbonate salts. It was found that ammonium carbonate salts have high displacing properties, the displacement ratio of kerosene by NH4HCO3 solution is 0.75-0.80, while reservoir water – 0.55-0.58. According to the results of laboratory studies of the displacing and washing characteristics of ammonium carbonate salts, conclusions were made about the effect of bicarbonate solution (ammonium carbonate salts) on the production characteristics of a well in reservoir conditions at temperatures of 80-100 °C and above. Industrial tests of ammonium carbonate salts showed an increase in gas flow by 30-50% at wells № 23 of Opishnia, № 115 of Mashivka, № 3 of Tymofiivka gas condensate fields. The effect of formation treatment with ammonium carbonate salts is achieved due to clearing of well bottom zone and increasing the formation permeability. At wells № 56, 108 of Yablunivka and № 58 of Tymofiivka gas condensate fields, an increase in the condensate ratio was observed by 22-35%. The effectiveness of this treatment is associated with the simultaneous bottomhole zone cleaning from asphalt-resinous contaminants and permeability increase, as well as with the hydrophilization of the pore space and mobility increase of condensate precipitated as a result of carbon dioxide effect, which was rejected as a result of decomposition of ammonium carbonate. Thus, experimental and industrial tests in Opishnia, Mashivka, Tymofiivka, Yablunivka gas condensate fields of Poltava region confirmed the effectiveness of using ammonium carbonate to increase hydrocarbon production. The prospect of further research is aimed at developing a technology for increasing the production of liquid hydrocarbons by using ammonium carbonate salts.


2017 ◽  
pp. 56-61
Author(s):  
M. L. Karnaukhov ◽  
O. N. Pavelyeva

The well testing of gas-condensate horizontal wells are discussed in the article and the comparative analysis of borehole flow capacity, depending on the mode of it’s operation is presented. Extra attention is focused on the issue of timely identification of the reasons for the reduction of fluid withdrawal from the reservoir. The presence of high skin effect is proved, which confirms the existence of low-permeability of bottomhole formation zone related to condensation in the immediate area of the horizontal wellbore.


Geophysics ◽  
2006 ◽  
Vol 71 (1) ◽  
pp. N11-N19 ◽  
Author(s):  
Ayako Kameda ◽  
Jack Dvorkin ◽  
Youngseuk Keehm ◽  
Amos Nur ◽  
William Bosl

Numerical simulation of laboratory experiments on rocks, or digital rock physics, is an emerging field that may eventually benefit the petroleum industry. For numerical experimentation to find its way into the mainstream, it must be practical and easily repeatable — i.e., implemented on standard hardware and in real time. This condition reduces the size of a digital sample to just a few grains across. Also, small physical fragments of rock, such as cuttings, may be the only material available to produce digital images. Will the results be meaningful for a larger rock volume? To address this question, we use a number of natural and artificial medium- to high-porosity, well-sorted sandstones. The 3D microtomography volumes are obtained from each physical sample. Then, analogous to making thin sections of drill cuttings, we select a large number of small 2D slices from a 3D scan. As a result, a single physical sample produces hundreds of 2D virtual-drill-cuttings images. Corresponding 3D pore-space realizations are generated statistically from these 2D images; fluid flow is simulated in three dimensions, and the absolute permeability is computed. The results show that small fragments of medium– to high-porosity sandstones that are statistically subrepresentative of a larger sample will not yield the exact porosity and permeability of the sample. However, a significant number of small fragments will yield a site-specific permeability-porosity trend that can then be used to estimate the absolute permeability from independent porosity data obtained in the well or inferred from seismic techniques.


The paper focuses on the filtration and electrical anisotropy coefficients and relationship between vertical and horizontal permeability in sandstone reservoir rocks. Field case study of DDB reservoir rocks. Petrophysical properties and parameters are estimated from core and log data from a Moscovian and Serpukhovian stages of Dnipro-Donetsk Basin (West-Shebelynka area well 701-Bis and South-Kolomak area well 31). Routine core analysis included estimation of absolute permeability, open porosity, irreducible water saturation and electrical resistivity (on dry and saturated by mineralized solution) of 40 core samples along two orthogonal directions. Shale fraction is estimated using well logging data in wells which are analyzed. The authors report that reservoir rocks are represented by compacted poor-porous (φ <10 %), low permeable (k<1mD) laminated sandstone with different ratios of clay minerals (Vsh from 0,03 to 0,7) and high volume of micaceous minerals (in some cases 20-30 %). Research theory. One of the main objectives of the work is to develop empirical correlation between vertical permeability and other capacitive and filtration properties for compacted sandstone reservoirs. A modified Kozeny-Carman equation and the concept of hydraulic average radius form the basis for the technique. Results. Coefficients of the anisotropy of gas permeability (IA) and electrical resistivity (λ) are defined based on the results of petrophysical studies. The experiments proved that IA lies in a range from 0,49 to 5 and λ from 0,77 to 1,06. Permeability and electrical resistivity anisotropy in most cases have horizontal distribution. It has been shown that in West-Shebelynka area sample №1 (depth 4933 m) there is probably no fluids flow in vertical direction and in samples №№3 and 15 fractures have the vertical orientation. We have also found that the values of electrical and filtration anisotropy for all samples of South-Kolomak area are similar, this characterized the unidirectionality in their filtration properties, as well as the fact that the motion of the fluid flow mainly in the horizontal direction. In the studied rocks the degree of anisotropy has been concluded to depend on the volume of clay and micaceous minerals, their stratification, fractures, density, and their orientation. New correlation between vertical permeability, horizontal permeability and effective porosity are developed for Late Carboniferous DDB intervals that are analyzed.


2017 ◽  
pp. 85-89 ◽  
Author(s):  
V. V. Panikarovskii ◽  
E. V. Panikarovskii

At late stage of development of gas fields they need to solve the specific issues of increasing the production rate of wells and decreasing water cut. The available experience of development of gas and gas condensate fields proves, that the most effective method of removing of water, accumulating in wells, is an injection into the bottom hole zone of foam-forming compositions, based on surfactants. The most technological in the application was the use of solid and liquid surfactants. Installation in wells of lift columns of smaller diameter ensured the removal of liquid from the bottom hole of wells, but after few month of exploitation the conditions of removal of liquid from the bottom hole of wells deteriorate. The technologies of concentric lift systems and plunger-lift systems are used in small number of wells. The basic technology for removal of liquid from bottom hole of gas wells at present time is the technology of treatment of bottom hole of wells with solid surfactants.


2020 ◽  
Vol 17 (34) ◽  
pp. 769-781 ◽  
Author(s):  
Karina Shamilevna KHAIBULLINA ◽  
Grigory Yurievich KOROBOV ◽  
Aleksandr Viktorovich LEKOMTSEV

The problem of the formation of asphalt-resin-paraffin deposits (ARPD) in oil fields within the “well – bottom-hole formation zone” system is still relevant. To prevent the formation of ARPD in the “bottom-hole formation zone – well” system, the ARPD inhibitors must have high adsorption and low desorption properties concerning the rock. The composition of inhibitors often includes surfactants. Nonionic surfactants, namely, polyesters, are widely used to prevent the formation of ARPD. However, currently, little is known about inhibitors with a combined effect, for example, possessing depressor-dispersing properties for ARPD. This work aimed to develop a combined inhibitor possessing not only depressor-dispersing properties but also having good adsorption and desorption properties to the rock to prevent the formation of ARPD. The paper presents the research results on the development of an ARPD inhibitor, as well as the effects of determination of its depressor dispersing, inhibiting, and corrosive properties; the temperature of oil saturation with paraffin is determined as well. The studies of the ARPD inhibitor adsorption were carried out by the static and dynamic methods. In contrast, the process of the inhibitor desorption was studied by oil filtering through a saturated sample of the rock using a bulk model and core material. The impact of the fluid flow rate on the inhibitor desorption rate was studied. The technological parameters of the ARPD inhibitor solution injection into the bottom-hole formation zone of production wells were calculated. The developed composition has high inhibiting properties concerning the ARPD, depressor dispersing properties, low corrosive activity for a metal surface, and is capable of lowering the temperature of oil saturation with paraffin.


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