scholarly journals Increasing the efficiency of water shut-off in oil wells using sodium silicate

2021 ◽  
pp. 26-31
Author(s):  
D. Zh. Abdeli ◽  
H. Daigle ◽  
A. S. Yskak ◽  
A. S. Dauletov ◽  
K. S. Nurbekova
Keyword(s):  
Sodium Silicate ◽  
Gelation Time ◽  
Full Scale ◽  
Oil Reservoir ◽  
Technological Processes ◽  
Scale Models ◽  
Production Wells ◽  
Reservoir Conditions ◽  
Water Blocking ◽  
Water Cut

Purpose. Substantiation of technology for creation of a water-blocking zone below an oil reservoir and calculation of the proper composition of a gel-forming compound based on sodium silicate, in order to reduce water cut in production wells. Methodology. The goal of the work was achieved by conducting theoretical and experimental studies on technological processes of water blocking in an oil reservoir, and by identifying patterns of gel formation of sodium silicate and hydration of a micro-cement solution in reservoir conditions on full-scale models. The gel compound included sodium silicate (Na2SiO3, also referred to as liquid glass) and an aluminum salt cross-linker (AS-1). The plugging material mixture of Portland micro-cement and sodium silicate contained calcium oxide, to allow expansion, and a GL-1 reaction inhibitor. The criteria for assessing the creation of a reliable water-blocking zone in an oil reservoir are: the mobility of the aqueous solution of the gel-forming compound during its movement from the wellhead to the bottom of the well, the low permeability of the zone following its creation, and the sufficient strength of the non-shrink micro-cement in the annulus of the well. Findings. A new technology is suggested used to create a water isolation zone is a gel-forming compound based on sodium silicate, which provides a significant reduction of water cut in oil production. It is found that perforation of production string below the oil reservoir at the level of the water-saturated zone followed by injection into a well through perforated channels, the mixture of fresh water and the gel-forming compound prevents water inflow to the bottom of the well. Experiments established that with a gelation time of 2 hours at a temperature of 80 C, the viscosity of the gel is in the range of 1.22.9 Pas, and the density is 10801109 kg/m3. These values for the viscosity of the gel allow transportation from the top of the well to the bottom with the least resistance to motion. Following gelation time, the viscosity increases significantly, and after 3 days the gel viscosity reaches a range of 3.46.7 Pas. The values indicated for the viscosity of the gel are much greater than those of oil. Therefore, the proposed gel-forming compound provides a reliable water shut-off zone at the bottom of an oil reservoir, and prevents the influx of water at the bottom of a well. Originality. The proposed sodium silicate compound allows for the creation of a reliable water shut-off zone and an enhanced grouting material, based on the combination of sodium silicate and micro-cement, which together provide a significant reduction in water cut in wells during oil production. Practical value. A method for studying technological processes of oil reservoir water-blocking has been devised and the rational composition of gel-forming compound and micro-cement grout slurry with an expanding additive and a reaction retarder in reservoir conditions on full-scale models has been established. The application of the research results in oil fields allows reduction of water cut in production wells to 010%, against existing values of 7090%, and an increase in flow rate in producing wells by 2030%.

scholarly journals CHANGE IN THE HYDROGEOCHEMICAL FIELD OF THE U1 HORIZON OF THE VERKH-TARSKOYE OIL FIELD IN THE PROCESS OF DEVELOPMENT

2021 ◽  
Vol 2 (1) ◽  
pp. 271-281
Author(s):  
Anastasiya S. Faustova ◽  
Dmitry A. Novikov ◽  
Svetlana A. Pavlova ◽  
Anatoliy V. Chernykh ◽  
Fedor F. Dultsev ◽  
...  
Keyword(s):  
Produced Water ◽  
Comprehensive Analysis ◽  
Oil Field ◽  
Oil Reservoir ◽  
Joint Operation ◽  
Production Wells ◽  
Cumulative Production ◽  
Main Production ◽  
Field Information ◽  
Water Cut

The results of a comprehensive analysis of geological and field information are presented in order to assess changes in the hydrogeochemical field of the oil reservoir of the U horizon of the Verkh-Tarskoye oil field during its development in the period from 1994 to 2021. The main production facility is at the IV stage of declining production. The water cut of the production wells stock reaches 98% with cumulative production of 14.86 million tons (as of May 1, 2021). Since 2015, there has been an increase in the TDS of produced water, which is explained by the processes of their mixing with circuit waters along the periphery of the reservoir with a decrease in reservoir pressure and more saline waters of the U horizon, supplied during joint operation.

Dynamic deformability evaluated by series of shaking table tests of full-scale models of masonry houses

2016 ◽  
pp. 2417-2424
Author(s):  
T. Hanazato ◽  
H. Seno ◽  
Y Niitsu ◽  
H. Imai ◽  
T. Narafu ◽  
...  
Keyword(s):  
Full Scale ◽  
Shaking Table ◽  
Shaking Table Tests ◽  
Scale Models

Failure tests on full-scale models of grout laminated wood decks

2004 ◽  
Vol 31 (1) ◽  
pp. 133-145 ◽  
Author(s):  
Aftab A Mufti ◽  
Baidar Bakht ◽  
Dagmar Svecova ◽  
Vidyadhar Limaye
Keyword(s):  
Load Distribution ◽  
Full Scale ◽  
Bottom Surface ◽  
Distribution Characteristics ◽  
Flat Bottom ◽  
The Third ◽  
Scale Models ◽  
Lower Load ◽  
Load Tests ◽  
The University

Grout laminated wood decks (GLWDs), representing the third generation of stressed wood decks, comprise either laminates or logs trimmed to obtain two parallel faces. The logs or laminates, running along the span, are held together by means of transverse internal grout cylinders that may be in either compression or tension. Two full-scale models of GLWD were constructed at Dalhousie University, Halifax, one with grout cylinders in compression and the other with the cylinders in tension. Service load tests conducted in Halifax showed that the former deck had better load distribution characteristics. Two years after the tests in Halifax, the models were shipped to The University of Manitoba in Winnipeg, where they were tested to failure under a central patch load. Because of miscommunication with the supplier, the logs of the GLWD with grout cylinders in compression were also trimmed to the third face that was kept at the bottom of the deck. The failure tests showed that despite its superior load distribution characteristics, the deck with grout cylinders in compression failed at a significantly lower load than the GLWD with cylinders in tension. It is argued that a planar surface in the logs at the flexural tension face not only reduces their flexural stiffness but also brings the defects of wood to the surface with maximum stress. The deck with the flat bottom surface underwent tension failure of the most heavily loaded logs, whereas the deck with the intact round surface of the logs at both top and bottom failed by horizontal splitting of all the logs.Key words: articulated plate, bridge deck, grout laminated deck, orthotropic plate, timber.

Overview of Performance and Analytical Modeling Techniques for Electromagnetic Heating and Applications to Steam-Assisted-Gravity-Drainage Process Startup

SPE Journal ◽  
2016 ◽  
Vol 21 (02) ◽  
pp. 311-333 ◽  
Author(s):  
Sahar Ghannadi ◽  
Mazda Irani ◽  
Rick Chalaturnyk
Keyword(s):  
High Viscosity ◽  
Gravity Drainage ◽  
Induction Medium ◽  
Oil Sand ◽  
Steam Assisted Gravity Drainage ◽  
Production Wells ◽  
Reservoir Conditions ◽  
Startup Time ◽  
Industry Practice ◽  
High Level

Summary Steam-assisted gravity drainage is the method of choice to extract bitumen from Athabasca oil-sand reservoirs in Western Canada. Under reservoir conditions, bitumen is immobile because of high viscosity, and its typically high level of saturation limits the injectivity of steam. In current industry practice, steam is circulated within injection and production wells. Operators keep the steam circulating until mobile bitumen breaks through the producer and communication is established between the injector and the producer. The “startup” phase is a time-consuming process taking three or more months with no oil production. A variety of processes could be used to minimize the length of the startup phase, such as electromagnetic (EM) heating in either the induction (medium frequency) or radio-frequency ranges. Knowledge of the size of the hot zone formed by steam circulation and of the benefits of simultaneous EM-heating techniques increases understanding of the startup process and helps to minimize startup duration. The aim of the present work is to introduce an analytical model to predict startup duration for steam circulation with and without EM heating. Results reveal that resistive (electrothermal) heating with/without brine injection cannot be a preferable method for mobilizing the bitumen in startup phase. Induction slightly decreases startup time at frequencies smaller than 10 kHz, and at 100 kHz it can reduce startup time to less than two months.

Innovations of Gas Lift in Prolific, Long-perforations, and Multilayered Wells, Case Study in Sudan

2016 ◽  
Author(s):  
Xueqing Tang ◽  
Lirong Dou ◽  
Ruifeng Wang ◽  
Jie Wang ◽  
Shengbao Wang ◽  
...  
Keyword(s):  
High Water ◽  
Water Breakthrough ◽  
Start Up ◽  
Production Wells ◽  
Decline Curves ◽  
High Water Cut ◽  
Water Cut ◽  
Gas Lift

ABSTRACT Jake field, discovered in July, 2006, contains 10 oil-producing and 12 condensate gas-producing zones. The wells have high flow capacities, producing from long-perforation interval of 3,911 ft (from 4,531 to 8,442 ft). Production mechanisms include gas injection in downdip wells and traditional gas lift in updip, zonal production wells since the start-up of field in July, 2010. Following pressure depletion of oil and condensate-gas zones and water breakthrough, traditional gas-lift wells became inefficient and dead. Based on nodal analysis of entire pay zones, successful innovations in gas lift have been made since March, 2013. This paper highlights them in the following aspects: Extend end of tubing to the bottom of perforations for commingled production of oil and condensate gas zones, in order to utilize condensate gas producing from the lower zones for in-situ gas lift.Produce well stream from the casing annulus while injecting natural gas into the tubing.High-pressure nitrogen generated in-situ was used to kick off the dead wells, instead of installation of gas lift valves for unloading. After unloading process, the gas from compressors was injected down the tubing and back up the casing annulus.For previous high water-cut producers, prior to continuous gas lift, approximately 3.6 MMcf of nitrogen can be injected and soaked a couple of days for anti-water-coning.Two additional 10-in. flow lines were constructed to minimize the back pressure of surface facilities on wellhead. As a consequence, innovative gas-lift brought dead wells back on production, yielding average sustained liquid rate of 7,500 bbl/d per well. Also, the production decline curves flattened out than before.

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