A Tool and Mathematical Model for Estimation of Wells Initial Water-Cut and Residual Oil Reserves on Large-Sized Oil Fields

2021 ◽  
Author(s):  
Vladimir Berezkin ◽  
Anar Sharifov ◽  
Elena Khatmullina ◽  
Evgeniy Yudin ◽  
Ildus Khatmullin
Keyword(s):  
Mathematical Model ◽  
Oil Fields ◽  
Accurate Estimation ◽  
Residual Oil ◽  
Initial Water ◽  
Oil Saturation ◽  
Oil Reserves ◽  
Production Forecasting ◽  
Intervention Planning ◽  
Water Cut

Abstract Oil production forecasting and well intervention planning require an accurate estimation of the remaining oil in place (ROIP). The problem of ROIP maps generation can be solved using commercial software; however, in the case of large fields, this requires significant computing resources and takes a big amount of time to prepare and adapt the data. Mathematical models for getting a quick solution to these issues have not been sufficiently elaborated. In this work a physical and mathematical model is proposed for building ROIP, oil saturation and water cut maps. The model was used to develop a tool for well stock managing, new wells drilling planning and detection of behind casing fluid flow by comparing the actual water cut of the well with the calculated water cut map.

scholarly journals Analysis of the directions for improving the development systems for oil fields at the later stage

2021 ◽  
Vol 1 (1(57)) ◽  
pp. 34-38
Author(s):  
Volodymyr Doroshenko ◽  
Oleksandr Titlov
Keyword(s):  
Late Stage ◽  
Water Movement ◽  
Oil Fields ◽  
Flow Profile ◽  
Residual Oil ◽  
Oil Reserves ◽  
Production Wells ◽  
Design Value ◽  
Oil Productivity ◽  
Water Cut

The object of research is oil fields at a late stage of their development. The most problematic issues in the development of oil fields are the formation and withdrawal of residual oil reserves. This problem is especially acute at the late or final stage, when the oil productivity of the wells decreases and the water cut of the production catastrophically increases. The most acceptable development system in such conditions is the use of methods for increasing oil recovery and, first of all, by injecting water into the reservoir. At the same time, the problematic issue is the lack of reliable information on the paths of water movement from injection to production wells and the imperfection of methods for aligning the injectivity profile in injection wells and the flow profile in production wells. In the course of the study, statistically analytical methods were used to analyze the state of development of oil fields at a late stage and industrial approbation of methods for tracing water movement and substantiation of a reagent base to align the paths of water movement and oil inflow. A set of reagents and technological methods for ensuring the regulation of the process of flooding of oil fields at a late stage of their development have been investigated and developed. It has been proven that a promising direction is the injection of a 0.1 % aqueous solution of the Polycar polymer together with water. This solution first of all penetrates into highly permeable, water-washed, formation intervals, contributing to the leveling of the injectivity profile, reducing the water cut of surrounding production wells and increasing their oil productivity. Thanks to the research carried out, directions and means of improving the systems of field development at a later stage have been developed by organizing targeted (selective) waterflooding of oil deposits based on high-quality and comprehensive control of the movement of filtration flows in the reservoir. This will ultimately contribute to achieving and maintaining the design value of reservoir pressure, preventing a decrease in the rate of decline in oil production, obtaining the design value of the sweep efficiency by waterflooding, and withdrawing residual oil reserves.

Estimating the effect of permeability variability of undersaturated oil reservoirs on the change in the start water-cut of well production

2020 ◽  
pp. 69-81
Author(s):  
I. M. Sagitova ◽  
D. K. Sagitov ◽  
Yu. V. Zeigman
Keyword(s):  
New Technologies ◽  
Water Saturation ◽  
Initial Period ◽  
Oil Reservoirs ◽  
Selective Isolation ◽  
Oil Saturation ◽  
Object A ◽  
Oil Reserves ◽  
Well Production ◽  
Water Cut

The development of undersaturated oil layered heterogeneous oil reservoirs against the background of a general depletion of oil reserves is becoming increasingly interesting. The development of these hard-to-recover oil reserves is associated with non-standard changes and increased water-cut in wells. An undersaturated (unformed, young) reservoir is a conditionally large transitional water-oil zone of the reservoir, in its classical sense. It is assumed that, since the initial oil saturation of the formation is low, and the water saturation is correspondingly high, the starting water cut should correspond to this ratio, but this is not so in some cases. At the same time, it is difficult to say in advance whether water-cut will increase, stabilize or fall in the first months. The study is aimed at identifying the determining parameter and the ranges of its change by statistical methods, based on which it will be possible to predict with high probability the nature of the change in water cut during the feasibility study for drilling new wells. For the conditions of the selected object, a graphical dependence of the water cut deviation in the initial period of well operation from layered heterogeneity of the reservoir is found. The results of the study are the rationale for creating new technologies for the selective isolation of oil-layers. It should to allow reversibly limiting the permeability of the low-permeability low-saturated part of the reservoir. Most of the existing technologies are aimed at the selective isolation of high-permeability and watered layers.

Classification of residual oil reserves and methods of its recovery

2021 ◽  
pp. 26-33
Author(s):  
D.Yu. Chudinova ◽  
◽  
Y.D.B. Atse ◽  
R.M. Minniakhmetova ◽  
M.Yu. Kotenev ◽  
...  
Keyword(s):  
Late Stage ◽  
Oil And Gas ◽  
Residual Oil ◽  
Oil Reserves ◽  
Oil And Gas Fields ◽  
Stage Of Development ◽  
Distribution Studies ◽  
Water Cut ◽  
Gas Fields ◽  
Technical Measures

Many oil and gas fields are currently at a late stage of development, while most of them are being developed using flooding. These fields are characterized by the decreasing oil and liquid flow rates and accelerating water-cut. During the development process, the majority of oil reserves are extracted not using methods of production enhancement. Though, oil reserves within undeveloped areas are a valuable source for recovery. To involve residual reserves in active development, it is necessary to make a reasonable justification and a choice of the most effective geological and technical measures that take into account various geological field and well reservoir characteristics. Residual oil reserves at the late stage of development are classified as hard-to-recover and are mainly concentrated in areas not covered by flooding laterally and vertically. They belong to various categories that differ in the geological and technological characteristics. In this regard, it is necessary to plan various geological and technical measures taking into account the structure of residual reserves and patterns of their distribution. Studies of complex oil and gas fields were performed and a detailed analysis of the geological and physical characteristics, parameters of reservoir heterogeneity along with operational, geological and commercial assessment of reserves development were conducted.

scholarly journals IDENTIFICATION OF INHOMOGENEOUS LAYERS AND RESERVOIR LENSES IN TERRIGENOUS DEPOSITS

Neft i gaz ◽  
2020 ◽  
Vol 1 (121) ◽  
pp. 25-39
Author(s):  
S.P. NOVIKOVA ◽  
◽  
S.V. SIDOROV ◽  
Z.M. RIZVANOVA ◽  
I.Z. FARXUTDINIV ◽  
...  
Keyword(s):  
Structural Factor ◽  
Upper Devonian ◽  
Residual Oil ◽  
Reservoir Properties ◽  
Systematic Analysis ◽  
Oil Saturation ◽  
Oil Reserves ◽  
Frasnian Stage ◽  
Net To Gross ◽  
Bypassed Oil

The possibilities of localizing residual oil reserves in depleted deposits of Tatarstan oilfield analyze in the article. The object of the study is the Pashian deposits of the Frasnian stage, Upper Devonian of the Almetyevskaya area, Romashkino oilfield. Possibilities of bypassed oil searching are considered. Sedimentation and heterogeneity of strata in the terrigenous Devonian sediments within the study area are analyzed in the paper. The analysis was carried out on the basis of well logging data. A detailed correlation of strata has been carried out, and members have been identified according to the rhythm of the layers’ occurrence in the Pashian horizon. The distribution of reservoirs and seals was studied based on the results of the detailed correlation. The analysis is based on a systematic analysis of the research object, which made it possible to consider the problem from different sides. The analysis of structural surfaces, maps of total and oil-saturated thicknesses, porosity, oil saturation, net-to-gross content and dissection along the upper and lower Pashian deposits was carried out. The influence of the structural factor on the reservoir properties of the formations is analyzed. The analysis made it possible to assess the heterogeneity of reservoirs in area and section and to predict the bypassed oil reserves localization.

scholarly journals Experimental Investigation of the Effect of Polymers on Residual Oil Saturation

SPE Journal ◽  
2017 ◽  
Vol 23 (01) ◽  
pp. 1-17 ◽  
Author(s):  
Heesong Koh ◽  
Vincent B. Lee ◽  
Gary A. Pope
Keyword(s):  
Low Cost ◽  
Flow Analysis ◽  
Reduction Factor ◽  
Residual Oil ◽  
Fractional Flow ◽  
Oil Saturation ◽  
Residual Oil Saturation ◽  
And Performance ◽  
Water Cut ◽  
Core Permeability

Summary Polymer flooding is a widely used commercial process with a low cost per barrel of produced oil, and hydrolyzed polyacrylamide (HPAM) polymers are the most widely used type of polymer. The objective of this research was to better understand and predict the behavior of HPAM polymers and their effect on residual oil saturation (ROS), to improve the capability of optimizing field design and performance. The corefloods were performed under typical field conditions of low pressure gradients and low capillary numbers. The polymer floods of the viscous oils recovered much more oil than the waterfloods, with up to 24% lower oil saturation after the polymer flood than after the waterflood. The experimental data are in good agreement with the fractional-flow analysis by use of the assumptions that the true ROSs and endpoint relative permeabilities are the same for both water and polymer. This suggests that, for more-viscous oils, the oil saturation at the end of a waterflood (i.e., at greater than 99% water cut) is better described as “remaining” oil saturation rather than the true “residual” oil saturation. This was true for all the corefloods, regardless of the core permeability and without the need for assuming a permeability-reduction factor in the fractional-flow analysis.

scholarly journals Forecast of water-cut at wells under design by machine learning methods

2019 ◽  
pp. 510-520
Author(s):  
M R Enikeev ◽  
M F Fazlytdinov ◽  
L V Enikeeva ◽  
I M Gubaidullin
Keyword(s):  
Machine Learning ◽  
Oil Industry ◽  
Well Logging ◽  
Oil Fields ◽  
Local Analysis ◽  
Learning Methods ◽  
Initial Water ◽  
Machine Learning Methods ◽  
Deterministic Methods ◽  
Water Cut

A large amount of data is generated during the operation of oil fields. Such data can be both data already interpreted by a specialist, or "raw” data obtained directly from the devices, both structured and not structured, or locally structured (that is, allowing for local analysis, but in such form not allowing analyzing in conjunction with other types of data). To obtain from such a set of more informative data that will allow making decisions in the course of field operation, it is necessary to involve specialists from different areas of the oil industry. Therefore, it is possible and necessary to use non-deterministic methods for analyzing the data obtained. The article discusses the use of machine learning methods in the task of determining the initial water-cut based on well logging data.

scholarly journals FEATURES OF APPLICATION OF MODEL OF THE STATIONARY TWO-PHASE FILTRATION FOR OIL FIELDS DEVELOPMENT

2017 ◽  
pp. 77-83
Author(s):  
V. A. Korotenko ◽  
S. I. Grachev ◽  
N. P. Kushakova
Keyword(s):  
Differential Equation ◽  
Water Saturation ◽  
Outer Boundary ◽  
Oil Fields ◽  
Two Phase ◽  
Flow Rates ◽  
Oil Saturation ◽  
Oil Flow ◽  
Water Cut ◽  
Filtration Model

The article discusses the differential equation of the stationary two-phase filtration, the obtained as a spe-cial case of nonlinear non-stationary equations. It is established that for the formulation of solutions it is necessary to use the dependence of water-saturation and oil-saturation factors on the pressure of water pumped into the reservoir. With the advance bringing into the development of the injection well, it has been established, that the water and oil flow rates and the water-cut coefficient depend on the selected coefficients of the relative permeability and the outer boundary of the drainage area. The merits and demerits of the stationary filtration model are estimated.

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