scholarly journals MATHEMATICAL MODELLING OF SCALING IN A RESERVOIR WHICH CONTAINS IMPERMEABLE LAYERS

2002 ◽  
Vol 1 (2) ◽  
pp. 15
Author(s):  
P. Bedrikovetsky ◽  
F. Rosario ◽  
M. Bezerra ◽  
M. Silva ◽  
R. Lopes Jr.
Keyword(s):  
High Velocity ◽  
Oil Fields ◽  
Formation Damage ◽  
Low Velocity ◽  
Tracer Concentration ◽  
Reservoir Water ◽  
Production Wells ◽  
Permeability Distribution ◽  
Impermeable Layer ◽  
Water Cut

Several different scenario of injected and reservoir water mixing have been proposed: mixing at high velocity near to injectors, mixing at low velocity inside reservoirs, mixing by diffusion via boundaries of layers with different permeabilities, mixing of injected, connate and aquifer waters at high velocity near to producers. Just the latter mechanism results in the accumulation of formation damage, while other mechanisms cause precipitation near to moving concentration front. In the current paper a new mechanism of oilfield scaling by diffusion of Barium from impermeable layer into the reservoir is proposed. The mechanism results in accumulation of precipitant and of formation damage. Viscous dominant regime of waterflooding takes place in the majority of oil fields. The Welge´s method allows calculating the permeability distribution from water cut history. The proposed extension to Welge´s method determines the partition of permeable layers in a reservoir from tracer concentration in production wells. Knowledge of this partition is important for modelling of oilfield scaling accounting for Barium supply from impermeable layers.

scholarly journals MATHEMATICAL MODELLING OF SCALING IN A RESERVOIR WHICH CONTAINS IMPERMEABLE LAYERS

2002 ◽  
Vol 1 (2) ◽  
Author(s):  
P. Bedrikovetsky ◽  
F. Rosario ◽  
M. Bezerra ◽  
M. Silva ◽  
R. Lopes Jr.
Keyword(s):  
High Velocity ◽  
Oil Fields ◽  
Formation Damage ◽  
Low Velocity ◽  
Tracer Concentration ◽  
Reservoir Water ◽  
Production Wells ◽  
Permeability Distribution ◽  
Impermeable Layer ◽  
Water Cut

Several different scenario of injected and reservoir water mixing have been proposed: mixing at high velocity near to injectors, mixing at low velocity inside reservoirs, mixing by diffusion via boundaries of layers with different permeabilities, mixing of injected, connate and aquifer waters at high velocity near to producers. Just the latter mechanism results in the accumulation of formation damage, while other mechanisms cause precipitation near to moving concentration front. In the current paper a new mechanism of oilfield scaling by diffusion of Barium from impermeable layer into the reservoir is proposed. The mechanism results in accumulation of precipitant and of formation damage. Viscous dominant regime of waterflooding takes place in the majority of oil fields. The Welge´s method allows calculating the permeability distribution from water cut history. The proposed extension to Welge´s method determines the partition of permeable layers in a reservoir from tracer concentration in production wells. Knowledge of this partition is important for modelling of oilfield scaling accounting for Barium supply from impermeable layers.

scholarly journals Design and Implementation of the Array Logging Tool on Horizontal Production Logging

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Wenguang Song ◽  
Haiyu Chen ◽  
Qiujuan Zhang ◽  
Jiahao Zhang
Keyword(s):  
Horizontal Wells ◽  
High Water ◽  
Oil Fields ◽  
Measuring Instruments ◽  
Conventional Production ◽  
Production Wells ◽  
Specific Retention ◽  
High Water Cut ◽  
Water Cut ◽  
Logging Tool

The measuring instruments have some errors in the measurement of high water cut production wells, and many domestic oil fields are also in high water cut state. The measured data from the conventional production logging instrument are all almost inaccurate. This project has designed a staggered probe array flow meter well logging apparatus based on the characteristic of electromagnetic wave specific retention meter that can fully cover the wellbore fluid and improve flow measurement accuracy. According to the application in horizontal wells, the accuracy of this measuring instrument now has been proved to be more than 90% and can meet the requirements of production logging interpretation in horizontal wells.

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.

Detection of effort maximality in adults performing isokinetic wrist flexion and extension

2021 ◽  
pp. 1-7
Author(s):  
Mercè Torra ◽  
Eduard Pujol ◽  
Anna Maiques ◽  
Salvador Quintana ◽  
Roser Garreta ◽  
...  
Keyword(s):  
High Velocity ◽  
Healthy Male ◽  
Wrist Flexion ◽  
Low Velocity ◽  
Wrist Extensor ◽  
Submaximal Effort ◽  
The Difference ◽  
Muscle Groups ◽  
Maximal Effort ◽  
Flexion And Extension

BACKGROUND: The difference between isokinetic eccentric to concentric strength ratios at high and low velocities (DEC) is a powerful tool for identifying submaximal effort in other muscle groups but its efficiency in terms of the wrist extensors (WE) and flexors (WF) isokinetic effort has hitherto not been studied. OBJECTIVE: The objective of the present study is to examine the usefulness of the DEC for identifying suboptimal wrist extensor and flexor isokinetic efforts. METHODS: Twenty healthy male volunteers aged 20–40 years (28.5 ± 3.2) were recruited. Participants were instructed to exert maximal and feigned efforts, using a range of motion of 20∘ in concentric (C) and eccentric (E) WE and WF modes at two velocities: 10 and 40∘/s. E/C ratios (E/CR) where then calculated and finally DEC by subtracting low velocity E/CR from high velocity ones. RESULTS: Feigned maximal effort DEC values were significantly higher than their maximal effort counterparts, both for WF and WE. For both actions, a DEC cutoff level to detect submaximal effort could be defined. The sensitivity of the DEC was 71.43% and 62.5% for WE ad WF respectively. The specificity was 100% in both cases. CONCLUSION: The DEC may be a valuable parameter for detecting feigned maximal WF and WE isokinetic effort in healthy adults.

scholarly journals Studying the Depth Structure of the Kyrgyz Tien Shan by Using the Seismic Tomography and Magnetotelluric Sounding Methods

Geosciences ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 122
Author(s):  
Irina Medved ◽  
Elena Bataleva ◽  
Michael Buslov
Keyword(s):  
Seismic Tomography ◽  
High Velocity ◽  
Fault Zones ◽  
Magnetotelluric Sounding ◽  
Tien Shan ◽  
High Resistivity ◽  
Low Velocity ◽  
Low Resistivity ◽  
Velocity Models ◽  
Fluid Saturation

This paper presents new results of detailed seismic tomography (ST) on the deep structure beneath the Middle Tien Shan to a depth of 60 km. For a better understanding of the detected heterogeneities, the obtained velocity models were compared with the results of magnetotelluric sounding (MTS) along the Kekemeren and Naryn profiles, running parallel to the 74 and 76 meridians, respectively. We found that in the study region the velocity characteristics and geoelectric properties correlate with each other. The high-velocity high-resistivity anomalies correspond to the parts of the Tarim and Kazakhstan-Junggar plates submerged under the Tien Shan. We revealed that the structure of the Middle Tien Shan crust is conditioned by the presence of the Central Tien Shan microcontinent. It manifests itself as two anomalies lying one below the other: the lower low-velocity low-resistivity anomaly, and the upper high-velocity high-resistivity anomaly. The fault zones, limiting the Central Tien Shan microcontinent, appear as low-velocity low-resistivity anomalies. The obtained features indicate the fluid saturation of the fault zones. According to the revealed features of the Central Tien Shan geological structure, it is assumed that the lower-crustal low-velocity layer can play a significant role in the delamination of the mantle part of the submerged plates.

scholarly journals THE ISSUE OF APPLICATION OF PHYSICAL AND CHEMICAL TECHNOLOGIES IN THE DEVELOPMENT OF OIL AND GAS FIELDS

2016 ◽  
pp. 71-74
Author(s):  
E. F. Zakharova ◽  
E. V. Levanova ◽  
G. N. Farkhutdinov
Keyword(s):  
Oil And Gas ◽  
High Water ◽  
Oil Fields ◽  
Chemical Methods ◽  
Oil And Gas Fields ◽  
Extraction Factor ◽  
High Water Cut ◽  
Water Cut ◽  
Gas Fields ◽  
Physical And Chemical

The efficiency of different physical and chemical technologies used in various areas and Romashkinskoye New-Elkhovskoye oil fields was researched. The result was a conclusion that at high water-cut objects, restriction of movement of water in highly permeable leached zones of a productive layer is one of the main conditions for increasing the efficiency of not only flooding, but also the use of physical and chemical methods based on improving of oil extraction factor.

Introduction

1958 ◽  
Vol 246 (1245) ◽  
pp. 146-154 ◽  
Keyword(s):  
High Velocity ◽  
Low Velocity ◽  
Transition Stage ◽  
Initiation Process ◽  
Stage 4

In this Discussion we are concerned with the mechanism by which an explosion can be initiated in a solid or liquid and can grow to a high-velocity detonation. It is convenient to divide the process into four stages: (1) initiation in some localized region; (2) the growth of the explosion; (3) a transition stage or low-velocity detonation which finally passes over to (4) a high-velocity stable detonation. Stage (4) has been dealt with at an earlier Discussion in this Society led by Sir William Penney (1950). Here we propose to concentrate our attention on (1), (2) and (3). We shall begin with the initiation process and then later in the Discussion go on to consider the growth to detonation.

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