Cyclic Production Scheme for High WC and Low-Pressure Wells for Reservoir Management

Abstract Lower Burgan (LB) is one of the most mature reservoirs in north Kuwait divided in to 3 layers, first layer under partial depletion drive and suffer from low reservoir pressure, the second layer under edge-partial water drive and the last layer under active water drive. Increasing trend of water production and high GOR has become a big challenge to control the reservoir production, several of studies done to evaluate the best strategy to enhance the reservoir performance. A comprehensive review of the performance of the wells was conducted to diagnose the specific reason and necessary remedial measures to be adopted. The review included the assessment of the results of the material balance and numerical simulation studies, depletion strategies, wettability/ relative permeability footprints; proximity to the OWC; past completion practices, well integrity and the time lapse PNC/PLT/ Well testing data. Workflows were developed for the sublayers within the hydraulic unit for systematic water cut diagnostics and preventive steps. Identification of suitable technology to address water cut and GOR management was also done. The typical trend of water cut and GOR performance with time and the depletion strategy was established to add value to the ongoing production activities and well allowable for each hydraulic unit. Rate sensitive performance was analyzed for the integration into the production plans. Cyclic production is identified as one of the new ways to reduce the water production and maintain the production for the wells producing below the bubble point. The concept was tried at high water cut wells successfully to revive the well from about 100% to 87% water cut with a closure cycle for 3 month and sustaining the production for high GOR wells with good ESP performance. In addition, suitable candidates have been identified for Coning Control Completions to weaken the water encroachment into the downhole wellbore. The overall water cut for the reservoir has been stabilized during last one year, thus helping the water handling constraints at the gathering facility. This paper will discuss the successful approach to control coning and water encroachment for active Bottom and Edge-Water drive layer and how this approached helped to sustain the production on high GOR wells running below bubble point with necessary diagnostics and remedial measures.

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New Gel Aggregates To Improve Sweep Efficiency During Waterflooding

SPE Reservoir Evaluation & Engineering ◽

10.2118/129960-pa ◽

2011 ◽

Vol 14 (01) ◽

pp. 120-128 ◽

Cited By ~ 20

Author(s):

Guanglun Lei ◽

Lingling Li ◽

Hisham A. Nasr-El-Din

Keyword(s):

Low Cost ◽

Oil Production ◽

High Water ◽

Resistance Factor ◽

Water Production ◽

Sweep Efficiency ◽

Low Viscosity ◽

Productivity Decline ◽

High Water Cut ◽

Water Cut

Summary A common problem for oil production is excessive water production, which can lead to rapid productivity decline and significant increases in operating costs. The result is often a premature shut-in of wells because production has become uneconomical. In water injectors, the injection profiles are uneven and, as a result, large amounts of oil are left behind the water front. Many chemical systems have been used to control water production and improve recovery from reservoirs with high water cut. Inorganic gels have low viscosity and can be pumped using typical field mixing and injection equipment. Polymer or crosslinked gels, especially polyacrylamide-based systems, are mainly used because of their relatively low cost and their supposed selectivity. In this paper, microspheres (5–30 μm) were synthesized using acrylamide monomers crosslinked with an organic crosslinker. They can be suspended in water and can be pumped in sandstone formations. They can plug some of the pore throats and, thus, force injected water to change its direction and increase the sweep efficiency. A high-pressure/high-temperature (HP/HT) rheometer was used to measure G (elastic modulus) and G" (viscous modulus) of these aggregates. Experimental results indicate that these microspheres are stable in solutions with 20,000 ppm NaCl at 175°F. They can expand up to five times their original size in deionized water and show good elasticity. The results of sandpack tests show that the microspheres can flow through cores with permeability greater than 500 md and can increase the resistance factor by eight to 25 times and the residual resistance factor by nine times. The addition of microspheres to polymer solutions increased the resistance factor beyond that obtained with the polymer solution alone. Field data using microspheres showed significant improvements in the injection profile and enhancements in oil production.

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New Waterflooding Characteristic Curves Based on Cumulative Water Injection

Mathematical Problems in Engineering ◽

10.1155/2020/7415236 ◽

2020 ◽

Vol 2020 ◽

pp. 1-12

Author(s):

Zhiwang Yuan ◽

Zhiping Li ◽

Li Yang ◽

Yingchun Zhang

Keyword(s):

Characteristic Curve ◽

Water Injection ◽

Material Balance ◽

Oil Production ◽

High Water ◽

Difficult Problem ◽

Prediction Errors ◽

High Water Cut Stage ◽

High Water Cut ◽

Water Cut

When a conventional waterflooding characteristic curve (WFCC) is used to predict cumulative oil production at a certain stage, the curve depends on the predicted water cut at the predicted cutoff point, but forecasting the water cut is very difficult. For the reservoirs whose pressure is maintained by water injection, based on the water-oil phase seepage theory and the principle of material balance, the equations relating the cumulative oil production and cumulative water injection at the moderately high water cut stage and the ultrahigh water cut stage are derived and termed the Yuan-A and Yuan-B curves, respectively. And then, we theoretically analyze the causes of the prediction errors of cumulative oil production by the Yuan-A curve and give suggestions. In addition, at the ultrahigh water cut stage, the Yuan-B water cut prediction formula is established, which can predict the water cut according to the cumulative water injection and solve the difficult problem of water cut prediction. The application results show Yuan-A and Yuan-B curves are applied to forecast oil production based on cumulative water injection data obtained by the balance of injection and production, avoiding reliance on the water cut forecast and solving the problems of predicting the cumulative oil production of producers or reservoirs that have not yet shown the decline rule. Furthermore, the formulas are simple and convenient, providing certain guiding significance for the prediction of cumulative oil production and water cut for the same reservoir types.

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Research on Methods of Separate Stratum Injection Allocation in High Water Cut Stage

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.868.645 ◽

2013 ◽

Vol 868 ◽

pp. 645-650

Author(s):

Lin Li

Keyword(s):

Material Balance ◽

High Water ◽

Small Error ◽

Oil Field ◽

Petroleum Reservoir ◽

Injection Wells ◽

Single Well ◽

High Water Cut Stage ◽

High Water Cut ◽

Water Cut

The parameters of reservoir impact all the sectors of oilfield developing after flood development, so methods of separate stratum injection allocation are researched for forecasting the petroleum reservoir performance accurately. The methods of separate stratum injection allocation are significative for remaining oil distribution, injection allocation of interval and the level of exploitation and administration in high water cut stage. First, we should derive injection-withdrawal ratio (IWR), gradient of pressure and water cut by material balance equation.The injection allocation of single well,injection wells and property of interval are determined by the research of split coefficient.We find the reservoir small error, lower water cut, high degree of reservoir recovery by anaysising the results of separate stratum injection allocation.The results show that separate stratum injection allocation is scientific and reasonable, simple and applied for the oil field in high water cut stage.

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Fieldwide Application of Autonomous Inflow Control Valve in Increasing the Field Recovery in One of the Matured Fields in the Sultanate of Oman: Case Study

10.2118/208179-ms ◽

2021 ◽

Author(s):

Salim Buwauqi ◽

Ali Al Jumah ◽

Abdulhameed Shabini ◽

Ameera Harrasi ◽

Tejas Kalyani ◽

...

Keyword(s):

Control Valve ◽

Oil Production ◽

Horizontal Wells ◽

High Water ◽

Lessons Learned ◽

Water Production ◽

Sultanate Of Oman ◽

Well Performance ◽

Reservoir Conditions ◽

Water Cut

Abstract One of the largest operators in the Sultanate of Oman discovered a clastic reservoir field in 1980 and put it on production in 1985. The field produces viscous oil, ranging from 200 - 2000+ cP at reservoir conditions. Over 75% of the wells drilled are horizontal wells and the field is one of the largest producers in the Sultanate of Oman. The field challenges include strong aquifer, high permeability zones/faults and large fluid mobility contrast have resulted that most of the wells started with very high-water cuts. The current field water cut is over 94%. This paper details operator's meticulous journey in qualification, field trials followed by field-wide implementation and performance evaluation of Autonomous Inflow Control Valve (AICV) technology in reducing water production and increasing oil production significantly. AICV can precisely identify the fluid flowing through it and shutting-off the high water or gas saturated zones autonomously while stimulating oil production from healthy oil-saturated zones. Like other AICDs (Autonomous Inflow Control Device) AICV can differentiate the fluid flowing through it via fluid properties such as viscosity and density at reservoir conditions. However, AICVs performance is superior due to its advanced design based on Hagen-Poiseuille and Bernoulli's principles. This paper describes an AICV completion design workflow involving a multi-disciplinary team as well as some of the field evaluation criteria to evaluate AICV well performance in the existing and in the new wells. The operator has completed several dozens of production wells with AICV technology in the field since 2018-19. Based on the field performance review, it has shown the benefit of accelerating oil production as well as reduction of unwanted water which not only reduces the OPEX of these wells but at the same time enormous positive impact on the environment. Many AICV wells started with just 25-40 % water cut and are still producing with low water cut and higher oil production. Based on the initial field-wide assessment, it is also envisaged that AICV wells will assist in achieving higher field recovery. Also, AICV helped in mitigating the facility constraints of handling produced water which will allow the operator continued to drill in-fill horizontal wells. Finally, the paper also discusses in detail the long-term performance results of some of the wells and their impact on cumulative field recovery as well as lessons learned to further optimise the well performance. The technology has a profound impact on improved sweep efficiency and as well plays an instrumental role in reducing the carbon footprint by reducing the significant water production at the surface. It is concluded that AICV technology has extended the field and wells life and proved to be the most cost-effective field-proven technology for the water shut-off application.

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An Innovated Water Shutoff Technology in Offshore Carbonate Reservoir

10.2118/204593-ms ◽

2021 ◽

Author(s):

Yong Yang ◽

Xiaodong Li ◽

Changwei Sun ◽

Yuanzhi Liu ◽

Renkai Jiang ◽

...

Keyword(s):

Heavy Oil ◽

Bottom Water ◽

High Water ◽

Carbonate Reservoir ◽

Oil Reservoir ◽

Water Production ◽

Water Shutoff ◽

Water Breakthrough ◽

Heavy Oil Reservoir ◽

Water Cut

Abstract The problem of water production in carbonate reservoir is always a worldwide problem; meanwhile, in heavy oil reservoir with bottom water, rapid water breakthrough or high water cut is the development feature of this kind of reservoir; the problem of high water production in infill wells in old reservoir area is very common. Each of these three kinds of problems is difficult to be tackled for oilfield developers. When these three kinds of problems occur in a well, the difficulty of water shutoff can be imagined. Excessive water production will not only reduce the oil rate of wells, but also increase the cost of water treatment, and even lead to well shut in. Therefore, how to solve the problem of produced water from infill wells in old area of heavy oil reservoir with bottom water in carbonate rock will be the focus of this paper. This paper elaborates the application of continuous pack-off particles with ICD screen (CPI) technology in infill wells newly put into production in brown field of Liuhua, South China Sea. Liuhua oilfield is a biohermal limestone heavy oil reservoir with strong bottom water. At present, the recovery is only 11%, and the comprehensive water cut is as high as 96%. Excessive water production greatly reduces the hydrocarbon production of the oil well, which makes the production of the oilfield decrease rapidly. In order to delay the decline of oil production, Liuhua oilfield has adopted the mainstream water shutoff technology, including chemical and mechanical water shutoff methods. The application results show that the adaptability of mainstream water shutoff technology in Liuhua oilfield needs to be improved. Although CPI has achieved good water shutoff effect in the development and old wells in block 3 of Liuhua oilfield, there is no application case in the old area of Liuhua oilfield which has been developed for decades, so the application effect is still unclear. At present, the average water cut of new infill wells in the old area reaches 80% when commissioned and rises rapidly to more than 90% one month later. Considering that there is more remaining oil distribution in the old area of Liuhua oilfield and the obvious effect of CPI in block 3, it is decided to apply CPI in infill well X of old area for well completion. CPI is based on the ICD screen radial high-speed fluid containment and pack-off particles in the wellbore annulus to prevent fluid channeling axially, thus achieving well bore water shutoff and oil enhancement. As for the application in fractured reef limestone reservoir, the CPI not only has the function of wellbore water shutoff, but also fills the continuous pack-off particles into the natural fractures in the formation, so as to achieve dual water shutoff in wellbore and fractures, and further enhance the effect of water shutoff and oil enhancement. The target well X is located in the old area of Liuhua oilfield, which is a new infill well in the old area. This target well with three kinds of water problems has great risk of rapid water breakthrough. Since 2010, 7 infill wells have been put into operation in this area, and the water cut after commissioning is 68.5%~92.6%. The average water cut is 85.11% and the average oil rate is 930.92 BPD. After CPI completion in well X, the water cut is only 26% (1/3 of offset wells) and the oil rate is 1300BPD (39.6% higher than that of offset wells). The target well has achieved remarkable effect of reducing water and increasing oil. In addition, in the actual construction process, a total of 47.4m3 particles were pumped into the well, which is equivalent to 2.3 times of the theoretical volume of the annulus between the screen and the borehole wall. Among them, 20m3 continuous pack-off particles entered the annulus, and 27.4m3 continuous pack-off particles entered the natural fractures in the formation. Through the analysis of CPI completed wells in Liuhua oilfield, it is found out that the overfilling quantity is positively correlated to the effect of water shutoff and oil enhancement.

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Polymer Application in High-Water-Cut Wells Enhances Productivity in a Mature Field

Journal of Petroleum Technology ◽

10.2118/0921-0060-jpt ◽

2021 ◽

Vol 73 (09) ◽

pp. 60-61

Author(s):

Chris Carpenter

Keyword(s):

Trinidad And Tobago ◽

Production Rate ◽

Produced Water ◽

Oil Production ◽

High Water ◽

Water Production ◽

Oil Viscosity ◽

High Stakes ◽

High Water Cut ◽

Water Cut

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 200957, “Application of Specially Designed Polymers in High-Water-Cut Wells: A Holistic Well-Intervention Technology Applied in Umm Gudair Field, Kuwait,” by Ali Abdullah Al-Azmi, SPE, Thanyan Ahmed Al-Yaqout, and Dalal Yousef Al-Jutaili, Kuwait Oil Company, et al., prepared for the 2020 SPE Trinidad and Tobago Section Energy Resources Conference, originally scheduled to be held in Port of Spain, Trinidad and Tobago, 29 June–1 July. The paper has not been peer reviewed. A significant challenge faced in the mature Umm Gudair (UG) field is assurance of hydrocarbon flow through highly water-prone intervals. The complete paper discusses the field implementation of a downhole chemical methodology that has positively affected overall productivity. The treatment was highly modified to address the challenges of electrical-submersible-pump (ESP)-driven well operations, technical difficulties posed by the formation, high-stakes economics, and high water potential from these formations. Field Background and Challenge The UG field is one of the major oil fields in Kuwait (Fig. 1). The Minagish oolite (MO) reservoir is the main oil producer, contributing more than 95% of current production in the UG field. However, water cut has been increasing (approximately 65% at the time of writing). The increasing water cut in the reservoir is posing a major challenge to maintaining the oil-production rate because of the higher mobility of water compared with that of oil. The natural water aquifer support in the reservoir that underlies the oil column extends across the reservoir and is rising continuously. This has led to a decline in the oil-production rate and has prevented oil-producing zones from contributing effectively. The reservoir experiences water-coning phenomena, especially in high-permeability zones. Oil viscosity ranges from 2 to 8 cp, and hydrogen sulfide and carbon dioxide levels are 1.5 and 4%, respectively. During recent years, water production has increased rapidly in wells because of highly conductive, thick, clean carbonate formations with low structural dip as well as some stratified formations. Field production may be constrained by the capacity of the surface facilities; therefore, increased water production has different effects on field operations. The average cost of handling produced water is estimated to be between $5 billion and $10 billion in the US and approximately $40 billion globally. These volumes often are so large that even incremental modifications can have major financial effects. For example, the lift-ing cost of one barrel of oil doubles when water cut reaches 50%, increases fivefold at 80% water cut, and increases twenty-fold at 95% water cut.

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The Analysis of Remaining Oil in High Water Cut Stage

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.274.675 ◽

2013 ◽

Vol 274 ◽

pp. 675-678

Author(s):

Cheng Fu ◽

Bin Huang

Keyword(s):

Characteristic Curve ◽

Material Balance ◽

High Water ◽

Oil Distribution ◽

Remaining Oil ◽

Remaining Oil Distribution ◽

High Water Cut Stage ◽

High Water Cut ◽

Water Cut ◽

Material Balance Method

The remaining oil distribution is very complex and the difficulty in tapping measures is more and more big when the west block of South-eight area has gone into the ultra-high water cut stage. So the remaining oil distribution in 109 units has been comprehensively studied on the condition that the composite water cut reaches 9.06% by establishing reservoir geologic model and proceeding reservoir numerical simulation according to recent tapping measures and remaining oil analysis experience in the process of adjusting scheme. And combined with some reservoir engineering methods such as: waterflooding characteristic curve and material balance method, obvious effects has been obtained in this research.

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Application of Specially Designed Polymers in High Water Cut Wells- A Holistic Well-Intervention Technology Applied in Umm Gudair Field, Kuwait

10.2118/200957-ms ◽

2021 ◽

Author(s):

Ali Abdullah Al-Azmi ◽

Thanyan Ahmed Al-Yaqout ◽

Dalal Yousef Al-Jutaili ◽

Kutbuddin Bhatia ◽

Amr Abdelbaky ◽

...

Keyword(s):

Best Practice ◽

Produced Water ◽

Positive Impact ◽

High Water ◽

Direct Result ◽

Water Production ◽

Well Test ◽

Field Development ◽

High Water Cut ◽

Water Cut

Abstract Excessive water production from hydrocarbon reservoirs is a serious issue faced by the industry, particularly for mature fields. Higher water cut adversely affects the economics of the producing wells, thus it is undesirable. Disposal and reinjection of ever-increasing volumes of produced water poses additional liability. A significant challenge faced in the mature Umm Gudair field is assuring hydrocarbon flow through high water-prone intervals. In recent times, field development strategies have begun to prioritize new well intervention technology because of the advantages of minimized water cut, higher production rates, and improved overall reserve recovery (hydrocarbon in place). This paper discusses the field implementation of a downhole chemical methodology, "first of its kind" designed and applied, that has created a positive impact in overall productivity. To solve these challenges, the treatment was highly modified as fit-for-purpose to address the unique challenges of electric submersible pump (ESP)-driven well operations, formation technical difficulties, high-stakes economics, and high-water potential from these formations. A unique Organically Crosslinked Polymer (OCP) system with a tail-in Rigid Setting Material (RSM) system was implemented as a porosity-fill sealant in a high-water-cut well to selectively reduce water production. A pre-flush was pumped ahead of the treatment to remove deposits that could have prevented the polymer from effective gelation. The treatment was then overdisplaced with brine. The OCP system is injected into the formation as a low viscosity solution using the spot and hesitation squeeze method via bullheading. It activates at a predicted time to form a 3-D rigid hydrogel to completely shut off matrix permeability, fractures, fissures, and channels, thus creating an artificial barrier seal in the reservoir. The tail-in near wellbore RSM system rapidly develops a high compressive strength to avoid any formation loss before setting. This holistic approach helps to create a robust sealant for blocking the unwanted water-producing zone, impeding water flow, and facilitating increased hydrocarbon flow. A direct comparison of the application of this system with conventional cement squeeze treatments is presented to illustrate the advantage of having a deep matrix penetration for a more efficient water shutoff in this field. A direct result of the implemented treatment is that the post-operation well test and production data showed a high-sustained production at lower rate with significantly reduced watercut, confirming this technology is one of successful chemical water shut off techniques this field. This paper summarizes the candidate selection, design processes, challenges encountered, and production response, and can be considered a best practice for addressing high water production challenges in similar conditions in other fields.

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Application of Autonomous Inflow Control Valve AICV in Increasing the Field Recovery in One of the Matured Fields in the Sultanate of Oman: Case Study

10.2118/207069-ms ◽

2021 ◽

Author(s):

Salim Buwauqi ◽

Ali Al Jumah ◽

Abdulhameed Shabibi ◽

Ameera Harrasi ◽

Tejas Kalyani ◽

...

Keyword(s):

Control Valve ◽

Oil Production ◽

Cost Effective ◽

High Water ◽

Water Production ◽

Sultanate Of Oman ◽

Viscous Oil ◽

Water Breakthrough ◽

Reservoir Conditions ◽

Water Cut

Abstract One of the largest clastic reservoir fields in the Sultanate of Oman has been discovered in 1980 and put on production in 1985. The field produces viscous oil, ranging from 200 - 2000+ cP at reservoir conditions. Over 75% of the wells drilled are horizontal wells and the field is one of the largest producers in the Sultanate of Oman. The field challenges include strong aquifer, high permeability zones/faults. Due to large fluid mobility contrast, the fields have experienced in pre-mature water breakthrough that has resulted in very high-water cuts. The average field water cut for open hole horizontal well after 6-9 months of production is over 94%. This paper details a meticulous journey in qualification, field trials followed by field-wide implementation and performance evaluation of Autonomous Inflow Control Valve (AICV) technology in reducing water production and increasing oil production significantly. AICV can precisely identify the fluid flowing through it and shutting-off the high water or gas saturated zones while producing oil from healthy oil-saturated zones. Like other AICDs (Autonomous Inflow Control Device) AICV can differentiate the fluid flowing through it via fluid properties such as viscosity and density at reservoir conditions. However, AICV's performance is superior due to its advanced design based on both Hagen-Poiseuille and Bernoulli's principles. This paper describes a comprehensive AICV completion design workflow that was developed across a multi-disciplinary team. Some of the initial wells completed with AICV has shown the benefit of accelerating oil production of over 30,000 bbls within the first few months of installation. Many wells started with 5-10 % water cut and are still producing with low water cut and higher oil production. The operator has approved AICV technology based on techno-commercial analysis and its positive impact on the project such as accelerated oil production and lower cost of water handling at the surface. AICV also helped in mitigating the facility constraints of handling produced water which resulted in reduce OPEX as allow the operator continued to drill horizontal wells. At the time of writing this paper, the operator has completed several dozen wells in the field with AICV technology and has an aggressive long term plan to complete several new and old wells. Finally, this paper also discusses in detail the comparative analysis of AICV wells for different subsurface conditions and share some lessons learned to further optimise the well performance. The technology has a profound impact on improved sweep efficiency and as well plays an instrumental role in reducing the carbon footprint by reducing the significant water production at the surface. It is concluded that AICV is a cost-effective field-proven technology for the water shut-off application. Due to its ability to autonomously identify and shut off water and gas production, the AICV technology has been approved to use as full fields implementation and in other fields. Field Background and Reservoir/Production challenges The operator produces around nine barrels of water against each produced barrel of oil. In general, the water produces to the surface with hydrocarbons contains many chemicals, which are usually not environmentally friendly and required additional treatment which increases the disposal cost. The Operator was looking for a cost-effective and proven technology that can control/shut off water production and improve oil production. The fields have a strong bottom aquifer and heterogeneous reservoir properties, such as permeability and downhole water saturation profiles. The challenge with matured brownfields, typically newly drilled wells will have pre-mature water breakthrough within few months of production. The fields have a highly viscous oil, with viscosity ranges from 200 cP up to 2000 cp at downhole conditions, thus creating a high mobility contrast between the oil and water, causing water fingering and coning at an early stage of production. These production challenges cause a significant recoverable oil left in the reservoir i.e. bypassed oil. Furthermore, excessive surface water production affects the integrated production system back pressures and flow, as well as an individual well's dynamics and pump efficiencies. This also has a significant downstream impact, where substantial investment is needed to handle, treat, and dispose of the water. Reducing these water volumes at the surface adds up to a tangible reduction in OPEX for water processing as well as environmentally friendly and assist the reservoir to maintain the reservoir pressure and energy by keeping the water in the reservoir. (Hilal et al 1997, Hassasi et al 2020)

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