Resolving Multiple Formation Damage Mechanism in Carbonate Reservoir Through Systematic Approach Using Combination of Aromatic Solvent and Less Aggressive Acid

2021 ◽  
Author(s):  
Hamzah Kamal ◽  
Prakoso Noke Fajar ◽  
Ghozali Farid ◽  
Aryanto Agus ◽  
Priyantoro Tri Atmojo ◽  
...  
Keyword(s):  
Systematic Approach ◽  
Oil Production ◽  
Damage Mechanism ◽  
Carbonate Reservoir ◽  
Formation Damage ◽  
Water Production ◽  
Aromatic Solvent ◽  
Well Productivity ◽  
Production Phase ◽  
Water Breakthrough

Abstract There is no well operation that is truly non-damaging. Any invasive operation, even production phase itself, may be damaging to well productivity. An interesting case was found in L-Field which is located in South Sumatra, Indonesia. All four wells are predicted to cease to flow after five-year production and artificial lift have to be installed to prevent steep decline in oil production. Unfortunately, all of wells’ productivity index (PI) decreased post well intervention and therefore, couldn’t achieve target. The PI was continuously decreasing during production phase and aggravated the decline in oil production. Remediation action by systematic approach was applied to solve the problem. Early diagnostic revealed some potential causes through evaluation of both production and well treatment data. Laboratory test such as mineralogy analysis, crude composition and water analysis, solubility and compatibility test have been conducted and clarified the root cause that formation damage occurred in multiple mechanism related to incompatibility of the workover fluid and organic deposition. Then, possible well treatments were listed with pros and cons by considering post water production related to the carbonate reservoir properties. Subsequently, chemical matrix injection was ranked based on less possibility of water breakthrough risk. Diesel fuel and de-emulsifier injection was decided as the first treatment in order to remove formation damage caused by organic deposition. The rate was increased temporary with Water Cut (WC) remained at the same level. The subseqeuent effort was to inject low reaction chelating acid and the result showed temporary improvement and the production did achieve significant gain. Finally, the third attempt indicated promising results with the injection of aromatic solvent followed by chelating acid. The well productivity was increased to more than 20 times of the pre treatment levels. The method can be replicated to other affected wells with similar damage mechanism. High vertical permeability over horizontal permeability becomes a real threat in carbonate strong water driver reservoir in L-field. Thus, matrix acidizing treatment has to be carefully applied to prevent unwanted water production. Non-aggressive and slow reaction acid were chosen to prevent face dissolution reaction that leads to water breakthrough.

scholarly journals Comparison Between Homogenous and Heterogeneous Reservoirs: A Parametric Study of Water Coning Phenomena

2021 ◽  
Vol 5 (1) ◽  
pp. 119-131
Author(s):  
Frzan F. Ali ◽  
Maha R. Hamoudi ◽  
Akram H. Abdul Wahab
Keyword(s):  
Production Rate ◽  
Oil Production ◽  
Water Production ◽  
Effective Parameters ◽  
Radial Cross Section ◽  
Heterogeneous Reservoirs ◽  
Water Breakthrough ◽  
Water Coning ◽  
Water Cut ◽  
Reservoir Simulator

Water coning is the biggest production problem mechanism in Middle East oil fields, especially in the Kurdistan Region of Iraq. When water production starts to increase, the costs of operations increase. Water production from the coning phenomena results in a reduction in recovery factor from the reservoir. Understanding the key factors impacting this problem can lead to the implementation of efficient methods to prevent and mitigate water coning. The rate of success of any method relies mainly on the ability to identify the mechanism causing the water coning. This is because several reservoir parameters can affect water coning in both homogenous and heterogeneous reservoirs. The objective of this research is to identify the parameters contributing to water coning in both homogenous and heterogeneous reservoirs. A simulation model was created to demonstrate water coning in a single- vertical well in a radial cross-section model in a commercial reservoir simulator. The sensitivity analysis was conducted on a variety of properties separately for both homogenous and heterogeneous reservoirs. The results were categorized by time to water breakthrough, oil production rate and water oil ratio. The results of the simulation work led to a number of conclusions. Firstly, production rate, perforation interval thickness and perforation depth are the most effective parameters on water coning. Secondly, time of water breakthrough is not an adequate indicator on the economic performance of the well, as the water cut is also important. Thirdly, natural fractures have significant contribution on water coning, which leads to less oil production at the end of production time when compared to a conventional reservoir with similar properties.

An Innovated Water Shutoff Technology in Offshore Carbonate Reservoir

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.

scholarly journals Analisis Peningkatan Produksi Pada Sumur Minyak Dengan Metode Partial Water Shut Off Dalam Meningkatkan Rasio Keberhasilan Partial Water Shut Off Pada Lapangan Hawa

2017 ◽  
Vol 6 (1) ◽  
pp. 44-48
Author(s):  
Fitrianti Fitrianti
Keyword(s):  
Water Treatment ◽  
Surface Water ◽  
Oil Production ◽  
Water Production ◽  
Well Productivity ◽  
Surface Water Treatment ◽  
Production History ◽  
Value Of Water ◽  
Partial Water

From year to year the number of oil production will be reduced and the amount of water production will grow, so will cause problems in managing the water. Some of the problems that arise are limitations in the surface water treatment systems, the availability of water treatment chemicals, and declining well productivity. Doing some work over to lower the value of water production and increase the value of oil production, one of which is the partial water shut off. On the hawa field, some job well done partial water shut off. The results of such work nothing works and nothing failed. Analysis performed on the job partial water shut off with the observation of the historycompletion and the processing of data and calculation of the value of production history OOIP to get the value of remaining reserves. After analysis, it was found some causes of work partial water shut off the well would be successful if it fulfills several criteria such as: the value of remaining reserves are still large enough, she had never done work partial water shut off in the layer and selecting the type of isolation right tool. While the cause of such failures is that the well had done work partial water shut off the same perforation interval. The criteria are very important and necessary in deciding the work partial water shut off the a better well done or not.

Application of Horizontal Wells to Reduce Water Production during Gel Treatment

2013 ◽  
Vol 807-809 ◽  
pp. 2629-2633
Author(s):  
Guang Xi Shen ◽  
Ji Ho Lee ◽  
Kun Sang Lee
Keyword(s):  
Oil Recovery ◽  
Substantial Reduction ◽  
Cross Flow ◽  
Oil Production ◽  
Horizontal Wells ◽  
Water Production ◽  
Sweep Efficiency ◽  
Vertical Permeability ◽  
Water Breakthrough ◽  
Gel Treatment

It is well known that gel treatment has outstanding potential to delay water breakthrough and reduce water production. However, it causes the decrease of oil production by permeability reduction, even though it is not as much as reduction of water production. For this reason, to improve oil production with substantial reduction of water production, performances of gel treatments through the combination of horizontal and/or vertical wells were assessed and compared. An extensive numerical simulation was executed for four different well configurations under gel treatment associated with waterflood to accomplish the purpose of this study. Performances were compared according to cumulative oil recovery and water-oil ratio at the production well for different systems. Though all of well configurations considered in this study effectively decreased the water production compared with waterflood, applications of horizontal wells led to much higher oil recovery than vertical well because of improved sweep efficiency. Based on these results, the potential of horizontal wells was examined through different scenarios in combinations of injection and production wells. Furthermore, various well lengths of injectors or producers were assessed for horizontal wells. Because cross-flow between layers dominates performance of gel treatment, effects of vertical permeability were also investigated in application of gel treatment with horizontal well. Longer wells and higher cross-flow results in better performance. This study represents that effectiveness of horizontal wells for gel treatment even for reservoirs having dominant cross-flow.

Autonomous Inflow Control Valve Applications Creating Better Wells: A Review of Design Optimization and Associated Benefits

2021 ◽  
Author(s):  
Mahmoud Abd El-Fattah ◽  
Ahmed Moustafa Fahmy ◽  
Hamed Wahaibi ◽  
Abdullah Shibli ◽  
Khaled Zuhaimi
Keyword(s):  
Control Valve ◽  
Oil Production ◽  
Horizontal Wells ◽  
Gas Production ◽  
Water Production ◽  
Gas Oil ◽  
Water Breakthrough ◽  
Effective Manner ◽  
Control Devices ◽  
Water Gas

Abstract One of the largest oil fields in the GCC was developed in the 1960's. The field was initially produced under natural depletion supplemented by gas injection. The high offtake rates led to a rapid displacement of the gas/oil contact; thus, the field has now been suffering from early gas/water breakthrough and uneven fluid influx along with the horizontal wells. The reservoir has been on production for more than 50 years. Water/gas breakthrough from fractures being the major challenge which negatively affects wells oil production rates. Applying technology which can manage water/gas breakthrough in a cost-effective manner whilst allowing increased oil production was a key goal from operators in this field. Passive Inflow Control Devices (ICD) were introduced to the global oil and gas market in mid/late-1990's, and the first generation of Autonomous ICD (AICD) that can help reduce more unwanted gas or water was first installed in 2007. ICD's successfully demonstrated that they could delay the gas and/or water breakthrough within horizontal wells, but they could not choke gas when the coning/gas-breakthrough occurred and along with limited abilities to stop unwanted water production. To help solve this problem, the Autonomous Inflow Control Devices (AICD-RCP) with a movable disc was introduced to the market and demonstrated reduction of gas production by 20-30% with similar gains in oil production[1]. In this paper, the newest generation of Autonomous Inflow Control Valve (AICV) technology is presented. The AICV technology has a movable piston that can close and reduce the unwanted gas and water production by up to 95%[2]. The application of AICVs discussed herein were deployed within several wells which had extremely high Gas Oil Ratio (GOR) and low oil production. The novel AICV technology can differentiate between fluid types based on viscosity and density. When undesired fluid (gas and/or water) starts to be produced, the AICV chokes the valve flow area gradually until completely shutting off, all without well intervention[3]. Well production performances are documenting the benefits of installing AICV completions. The results demonstrate the AICVs closing the zones with high gas production and favoring oil-rich zones. Majority of evaluated wells demonstrated clearly that the extremely high GOR was reduced; some wells have returned to solution GOR for more than two years, and at the same time, the daily oil production is increased.

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

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)

Innovative Completion Design and Systematic Approach Improves Operating Efficiency and Enhances Well Productivity

2009 ◽  
Author(s):  
Dickson Utomhin Omonze ◽  
Michael Roderick Jackson ◽  
Gildardo Osorio ◽  
Eduardo R. Blanco
Keyword(s):  
Systematic Approach ◽  
Operating Efficiency ◽  
Well Productivity

New Gel Aggregates To Improve Sweep Efficiency During Waterflooding

2011 ◽  
Vol 14 (01) ◽  
pp. 120-128 ◽  
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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