Field Performances, Effective Times, and Economic Assessments of Polymer Gel Treatments in Controlling Excessive Water Production From Mature Oil Fields

2020 ◽  
Vol 143 (8) ◽  
Author(s):  
Munqith Aldhaheri ◽  
Mingzhen Wei ◽  
Ali Alhuraishawy ◽  
Baojun Bai
Keyword(s):  
Fractured Reservoirs ◽  
Descriptive Analysis ◽  
Naturally Fractured Reservoirs ◽  
Oil Fields ◽  
Water Production ◽  
Polymer Gel ◽  
Rock Formations ◽  
Water Cut ◽  
Matrix Rock ◽  
Excessive Water

Abstract Polymer bulk gels have been widely applied to mitigate excessive water production from mature oil fields by correcting the reservoir permeability heterogeneity. This paper reviews water responses, effective times, and economic assessments of injection-well gel treatments based on 61 field projects. Eight parameters were evaluated per the reservoir type using the descriptive analysis, stacked histograms, and scatterplots. Results show that water production generally continues to increase after the treatment for undeveloped conformance problems. Contrarily, it typically decreases after the reactive gel treatments target developed conformance issues. For the developed problems, gel treatments do not always mitigate the water production where the water cut may stabilize or increase by 17% in 22% of instances. In addition, they often do reduce water production but not dramatically to really low levels where the water cut stays above 70% and reduces by only 10% in most cases. Gel treatments are economically appraised based only on the oil production response, and both water responses (injection and production) are not considered in the evaluation. They have a typical payout time of 9.2 months, cost of incremental oil barrel of 2 $/barrel, and effective time of 1.9 years. In addition, they have better water responses and economics in carbonates than in sandstones and in unconsolidated and naturally fractured reservoirs than in matrix-rock formations. The current review strongly warns reservoir engineers that gel treatments are not superior in alleviating the water production and candidates should be nominated based on this fact to achieve favorable economics and avoid treatment failures.

Stabilized Water-Cut in Carbonate Naturally-Fractured Reservoirs With Bottom Water With an Implication in Well Spacing Design for Recovery Optimization

2018 ◽  
Author(s):  
Samir Prasun ◽  
A. K. Wojtanowicz
Keyword(s):  
Final Stage ◽  
Bottom Water ◽  
Fractured Reservoirs ◽  
Capillary Forces ◽  
Naturally Fractured Reservoirs ◽  
Oil Displacement ◽  
Well Spacing ◽  
Constant Rate ◽  
Water Coning ◽  
Water Cut

Maximum stabilized water-cut (WC), also known as ultimate water-cut in a reservoir with bottom-water coning, provides important information to decide if reservoir development is economical. To date, theory and determination of stabilized water-cut consider only single-permeability systems so there is a need to extend this concept to Naturally Fractured Reservoirs (NFRs) in carbonate rocks — known for severe bottom water invasion. This work provides insight of the water coning mechanism in NFR and proposes an analytical method for computing stabilized water-cut and relating to well-spacing design. Simulated experiments on a variety of bottom-water hydrophobic NFRs have been designed, conducted, and analyzed using dual-porosity/dual-permeability (DPDP) commercial software. They show a pattern of water cut development in NFR comprising the early water breakthrough and very rapid increase followed by water cut-stabilization stage, and the final stage with progressive water-cut. The initial steply increase of water-cut corresponds to water invading the fractures. The stabilized WC production stage occurs when oil is displaced at a constant rate from matrix to the water-producing fractures. During this stage water invades matrix at small values of capillary forces so they do not oppose water invasion. In contrast, during the final stage (with progressing water cut) the capillary forces grow significantly so they effectively oppose water invasion resulting in progressive water cut. A simple analytical model explains the constant rate of oil displacement by considering the driving effect of gravity and viscous forces at a very small value of capillary pressure. The constant oil displacement effect is confirmed with a designed series of simulation experiments for a variety of bottom-water NFRs. Statistical analysis of the results correlates the duration of the stabilized WC stage with production rate and well-spacing and provides the basis for optimizing the recovery. Results show that stabilized water-cut stage does not significantly contribute to recovery, so the stage needs to be avoided. Proposed is a new method for finding the optimum well spacing that eliminates the stabilized WC stage while maximizing recovery. The method is demonstrated for the base-case NFR.

scholarly journals Experimental evaluation and tomographic characterization of polymer gel conformance treatment

2020 ◽  
Vol 75 ◽  
pp. 65
Author(s):  
Mina Kalateh-Aghamohammadi ◽  
Jafar Qajar ◽  
Feridun Esmaeilzadeh
Keyword(s):  
Pore Space ◽  
Ct Images ◽  
Water Salinity ◽  
Water Production ◽  
Polymer Gel ◽  
Formation Water ◽  
High Permeability ◽  
Conformance Control ◽  
Formation Water Salinity ◽  
Excessive Water

Excessive water production from hydrocarbon reservoirs is considered as one of major problems, which has numerous economic and environmental consequences. Polymer-gel remediation has been widely used to reduce excessive water production during oil and gas recovery by plugging high permeability zones and improving conformance control. In this paper, we investigate the performance of a HPAM/PEI (water-soluble Hydrolyzed PolyAcrylaMide/PolyEthyleneImine) polymer-gel system for pore space blockage and permeability reduction for conformance control purpose. First, the gel optimum composition, resistance to salt and long life time are determined using bottle tests as a standard method to specify polymer-gel properties. Then the performance and stability of the optimized polymer-gel are tested experimentally using coreflood tests in sandpack core samples. The effects of different parameters such as gel concentration, initial permeability of the cores, and formation water salinity on the final permeability of the cores are examined. Finally, the gel flow-induced local porosity changes are studied in both a sandpack core and a real carbonate sample using grayscale intensity data provided from 3D Computed Tomography (CT) images in pre- and post-treatment states. The results show that the gel system has a good strength at the middle formation water salinity (in the range of typical sea water salinity). In addition, despite a higher performance in high permeability cores, the gel resistance to degradation in such porous media is reduced. The CT images reveal that the initial porosity distribution has a great influence on the performance of the gel to block the pore space.

scholarly journals THE STUDY OF THE DEPENDENCE OF THE RHEOLOGICAL PROPERTIES OF GELFORMING COMPOSITIONS ON THE CRACK OPENING WHEN MODELING THEIR FLOW ON A ROTATIONAL VISCOMETER

2020 ◽  
Vol 17 (34) ◽  
pp. 933-939 ◽  
Author(s):  
Artem Maratovich SHAGIAKHMETOV ◽  
Dmitry Georgievich PODOPRIGORA ◽  
Andrey Victorovich TERLEEV
Keyword(s):  
Rheological Properties ◽  
Fractured Reservoirs ◽  
Crack Opening ◽  
Oil Production ◽  
High Water ◽  
Carbonate Reservoirs ◽  
Polymer Gel ◽  
Injection Wells ◽  
Rotational Viscometer ◽  
Water Cut

The current period of oil production is characterized by the deterioration of the structure of oil reserves because of high water cut of the product and low oil production rates. To reduce the increased water cut, repair and insulation works are often performed. This implies in the injection of cross-linked polymer systems or the treatment of the bottom hole formation zone with polymer-gel systems. This problem is especially relevant for fractured reservoirs, which are often represented by carbonate rocks. This article is devoted to the study of the dependence of the rheological properties of gel-forming compositions on the crack opening in carbonate reservoirs. The relevance of the work relies on the rapid involvement in the development of oil fields with carbonate reservoirs which is complicated by a large number of cracks of various sizes. The types of fractured reservoirs, the development features of each type, as well as complications in the hydrocarbon production from the fracturedpore structure of the reservoir were described. The research also pointed methods and technologies for limiting water flow in cracks or pores of high permeability. The rheological properties of fluids when moving inside pores and cracks were reported. The dependence of changes in the rheological properties of the composition for limiting water inflow based on carboxymethylcellulose on the size of pores, caverns and cracks were presented. The physics of movement and formation of gel inside the fractured reservoirs, which will allow predicting changes in the gel formation time and plastic strength for each object individually was described. According to this study, it is possible to use the features of the rheological properties of gel-forming compositions to increase the efficiency of the use of water-proofing technologies for producing wells, or to align the injectivity profile of injection wells.

Stabilized Water-Cut in Carbonate Naturally Fractured Reservoirs With Bottom Water With an Implication in Well Spacing Design for Recovery Optimization

2020 ◽  
Vol 142 (3) ◽  
Author(s):  
Samir Prasun ◽  
Andrew K. Wojtanowicz
Keyword(s):  
Final Stage ◽  
Bottom Water ◽  
Fractured Reservoirs ◽  
Capillary Forces ◽  
Naturally Fractured Reservoirs ◽  
Oil Displacement ◽  
Well Spacing ◽  
Constant Rate ◽  
Water Coning ◽  
Water Cut

Abstract Maximum stabilized water-cut (WC), also known as ultimate water-cut in a reservoir with bottom-water coning, provides important information to decide if reservoir development is economical. To date, theory and determination of stabilized water-cut consider only single-permeability systems so there is a need to extend this concept to naturally fractured reservoirs (NFRs) in carbonate rocks—known for severe bottom-water invasion. This work provides insight of the water coning mechanism in NFR and proposes an analytical method for computing stabilized water-cut and relating to well-spacing design. Simulated experiments on a variety of bottom-water hydrophobic NFRs have been designed, conducted, and analyzed using the dual-porosity/dual-permeability (DPDP) commercial software. They show a pattern of water-cut development in NFR comprising the early water breakthrough and very rapid increase followed by water-cut stabilization stage, and the final stage with progressive water-cut. The initial steply increase of water-cut corresponds to water invading the fractures. The stabilized WC production stage occurs when oil is displaced at a constant rate from matrix to the water-producing fractures. During this stage, water invades matrix at small values of capillary forces so they do not oppose water invasion. In contrast, during the final stage (with progressing water cut), the capillary forces grow significantly so they effectively oppose water invasion resulting in progressive water cut. A simple analytical model explains the constant rate of oil displacement by considering the driving effect of gravity and viscous forces at a very small value of capillary pressure. The constant oil displacement effect is confirmed with a designed series of simulation experiments for a variety of bottom-water NFRs. Statistical analysis of the results correlates the duration of the stabilized WC stage with production rate and well-spacing and provides the basis for optimizing the recovery. Results show that stabilized water-cut stage does not significantly contribute to recovery, so the stage needs to be avoided. Proposed is a new method for finding the optimum well spacing that eliminates the stabilized WC stage while maximizing recovery. The method is demonstrated for the base-case NFR.

scholarly journals A comprehensive review of the chemical-based conformance control methods in oil reservoirs

2021 ◽  
Vol 11 (5) ◽  
pp. 2233-2257
Author(s):  
Perekaboere Ivy Sagbana ◽  
Ahmad Sami Abushaikha
Keyword(s):  
Oil Recovery ◽  
Technical Problem ◽  
Field Application ◽  
Oil Fields ◽  
Control Methods ◽  
Polymer Gel ◽  
Conformance Control ◽  
Comprehensive Review ◽  
Oil Companies ◽  
Water Cut

AbstractThe production of excess water during oil recovery creates not only a major technical problem but also an environmental and cost impact. This increasing problem has forced oil companies to reconsider methods that promote an increase in oil recovery and a decrease in water production. Many techniques have been applied over the years to reduce water cut, with the application of chemicals being one of them. Chemicals such as polymer gels have been widely and successfully implemented in several oil fields for conformance control. In recent years, the application of foam and emulsions for enhanced oil recovery projects has been investigated and implemented in oil fields, but studies have shown that they can equally act as conformance control agents with very promising results. In this paper, we present a comprehensive review of the application of polymer gel, foam and emulsion for conformance control. Various aspects of these chemical-based conformance control methods such as the mechanisms, properties, applications, experimental and numerical studies and the parameters that affect the successful field application of these methods have been discussed in this paper. Including the recent advances in chemical-based conformance control agents has also been highlighted in this paper.

scholarly journals Development of fly ash reinforced nanocomposite preformed particle gel for the control of excessive water production in the mature oil fields

2019 ◽  
Vol 74 ◽  
pp. 8 ◽  
Author(s):  
Abhinav Kumar ◽  
Vikas Mahto ◽  
Virender Parkash Sharma
Keyword(s):  
Fly Ash ◽  
Critical Shear Stress ◽  
Oil Fields ◽  
Water Production ◽  
Sweep Efficiency ◽  
Improvement Rate ◽  
Preformed Particle Gel ◽  
Flow Experiment ◽  
Thermal Stability Of ◽  
Excessive Water

One of the appropriate methods to minimize water production and increase sweep efficiency is the utilization of Preformed Particle Gel (PPG) in the mature oil fields. In this paper, a new fly ash reinforced nanocomposite PPG was developed by the reaction of acrylamide as monomer, N,N′-Methylenebis (acrylamide) as crosslinker and nano fly ash in presence of Potassium Persulfate as initiator and it was compared with a conventional PPG which was designed without nano fly ash. On the incorporation of nano fly ash, swelling performance and thermal stability of PPG had increased significantly. Rheological data revealed that dynamic moduli (G′ and G″) of fly ash reinforced nanocomposite PPG has improved viscoelastic properties with a higher value of critical shear stress as compared to conventional PPG. The single sandpack flow experiment has shown the injectivity of nanocomposite PPG into the sandpack with a maximum resistance factor of 60.57. However, parallel-sandpack flow experiment showed that the newly developed nano fly ash reinforced nanocomposite PPG has a profile improvement rate of 92.98% and 97.83% for the permeability contrast of 2.16 and 4.14 respectively and hence it may be a promising agent in reducing excessive water production in mature oil fields.

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