First Time Worldwide Application of Glass Reinforced Epoxy Lined Tubing for Prevention of Asphaltene Deposition on Tubing in Oil Wells – A Case Study from Kuwait

2021 ◽  
Author(s):  
Reji Edappillikulangara Chinnappan ◽  
Milan Telang ◽  
Riyad Quttainah ◽  
Gokulnath Radhakrishnan ◽  
Alwyn Fernandes ◽  
...  

Abstract Asphaltene deposition in production tubing is a major flow assurance challenge. Common strategies to mitigate Asphaltene deposition downhole include mechanical or solvent cleanouts and chemical inhibition. These are associated with production deferment, high job costs, HSE risks and operational issues. In a worldwide first, Kuwait Oil Company (KOC) has addressed this challenge using Fiberglass (GRE) Lined Production Tubing. This technology was implemented in two trial wells. This paper chronicles the different mitigation strategies employed by KOC and presents the findings of the above-mentioned successful trials. Tendency of scale to stick on smoother, non-metallic surfaces, is known to be less than on bare steel surface. KOC had trialed internal coating to mitigate Asphaltene deposition in tubing, but the experience was not satisfactory. KOC has been successfully using GRE lined tubing for corrosion protection and scale prevention in oil and water wells. Considering GRE's smoother surface, lower zeta energy and thermal insulation, it was decided to conduct a trial of GRE lined tubing in wells with Asphaltene deposition problems. Frequency of cleanout and Well Head Pressure (WHP) trends, before and after installation of GRE Lined Tubing, were compared for evaluation. The paper chronicles the trial results and provides a comparison of implementation costs against currently employed tubing cleanouts by Coiled Tubing (CT) using a Diesel-Toluene mixture. Two wells, requiring frequent tubing cleanout of Asphaltene, were selected as candidates. Trends over a period of 13-15 months after installation of GRE lined tubing showed up to 74 % reduction in WHP decline rate compared to pre-installation periods. Cleanouts were avoided against an earlier frequency of 3 to 3.5 jobs per year. This resulted in following benefits: (1) Direct annual operational savings of 519,750 US $ per well (2) Additional production by increased uptime of 1 to 1 ½ months (3) Avoidance of Coiled Tubing sticking, occurring in similar wells, and the resultant workover cost (4) Eliminating production deferment due to this workover (5) An environment friendly and safe methodology not requiring handling of toxic, highly flammable Toluene, used for the clean outs. Comparison of the economics show clear-cut benefits of GRE lined tubing over tubing cleanouts. In view of the applicability in most of their high API gravity Jurassic oil wells, KOC has decided on wide scale implementation of this technology. As this is the first known case of its kind worldwide, we expect that this paper will be highly beneficial to operators faced with challenges in producing Asphalteinic oil and those engaged in CO2 EOR campaigns. Besides sharing experience, the authors aim to generate global operator engagement to optimize this new solution, possibly combined with other solutions, to tackle Asphaltene deposition as efficiently as possible.

2021 ◽  
Vol 73 (07) ◽  
pp. 55-56
Author(s):  
Chris Carpenter

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper IPTC 21441, “First-Time Worldwide Application of Glass-Reinforced Epoxy-Lined Tubing for Prevention of Asphaltene Deposition in Tubing in Oil Wells: A Case Study From Kuwait,” by Reji E. Chinnappan, SPE, Milan Telang, SPE, and Riyad Quttainah, SPE, Kuwait Oil Company, et al., prepared for presentation at the virtual 2021 International Petroleum Technology Conference, 23 March–1 April. The paper has not been peer reviewed. Copyright 2021 International Petroleum Technology Conference. Reproduced by permission. Asphaltene deposition in production tubing represents a major flow-assurance challenge. Common strategies to mitigate asphaltene deposition downhole include mechanical or solvent cleanouts and chemical inhibition. These are associated with production deferment, high job costs, safety and environmental risks, and operational issues. An operator has addressed this challenge using production tubing lined with glass-fiber-reinforced epoxy (GRE). This technology was implemented in two trial wells. The paper describes the different mitigation strategies employed by the operator and presents the findings of successful trials. Background Jurassic wells of a Kuwait Oil Company asset are producing light crude from a tight matrix-type reservoir located at a depth of 13,000–15,000 ft. Reservoir pressure has depleted from approximately 9,500–10,000 psi to approximately 6,000 psi because of sustained production in the absence of any significant pressure support. Oil production rates per well have diminished to the 500- to 1,000-BOPD range. The oil features high asphaltene onset pressures (4,000–5,000 psi). When considering time-lapse plots of caliper logs from a well where asphaltene deposition used to occur, the plot indicates that significant asphaltene deposition in the well took place below 4,500 ft and progressively increased over time. In approximately 5 months, the average internal diameter of the tubing reduced from 2.75 in. to less than 2 in., thereby constricting the flow significantly and requiring cleaning of the tubing. In extreme cases, the tubing string could be fully plugged. Many field trials with different tools and chemicals using batch and continuous treatment have been conducted in past years to solve this problem but without satisfactory results. Application of GRE-Lined Tubing for Asphaltene Control The operator decided to apply a novel strategy of using tubing internally lined with GRE based on its established ability to retard, and even eliminate, scale nucleation and deposition. The technology uses a thin-walled, solid-filament-wound GRE/fiberglass tube run inside carbon steel production tubing. Cement is pumped into the annulus between the steel tubing and the GRE liner. The ability to prevent asphaltene from sticking to the inner wall of the tubing is attributed to the smoother internal surface. It is also corroborated by a higher Hazen Williams coefficient value of 150 for GRE as compared with 110 for carbon steel pipe, which provides for lesser frictional pressure loss during flow. The GRE liners used by the operator have a surface roughness of 0.00011 in., which, unlike bare steel, is retained over the life of the GRE. The GRE-lined tubing proved to withstand temperatures of up to 280°F and hydrogen sulfide concentrations of up to 50%. This is comfortably more than the process conditions for the trial wells in consideration.


Author(s):  
I McCourt ◽  
J Kubie

To carry out remedial work in oil wells through the production tubing string, a method using a continuous length of steel coiled tubing is used. In horizontal wells substantial friction forces are generated which resist the motion of the tubing as it is pushed into the well. As the penetration increases, the friction forces arising from the contact of the tubing with the inner casing wall increase too, and the tubing buckles. The buckling is initially sinusoidal but eventually transforms into helical. At this point the force required to push the tubing rises dramatically, and the maximum penetration is then rapidly reached. Considerable economic benefits could be gained if the limits on the maximum penetration of coiled tubing in horizontal oil wells could be increased. This article discusses ways of increasing the penetration of coiled tubing in horizontal oil wells by managing the geometry of the coiled tubing. It is shown that the best strategy is to keep the external diameter of the coiled tubing constant, and to make up the coiled tubing from several sections, each with uniform, but increased wall thickness. It is shown that with two sections the maximum penetration can be increased by about half, and that with three sections the maximum penetration can be increased by about two-thirds.


2021 ◽  
Author(s):  
Seng Wei Jong ◽  
Yee Tzen Yong ◽  
Yusri Azizan ◽  
Richard Hampson ◽  
Rudzaifi Adizamri Hj Abd Rani ◽  
...  

Abstract Production decline caused by sand ingress was observed on 2 offshore oil wells in Brunei waters. Both wells were completed with a sub-horizontal openhole gravel pack and were subsequently shut in as the produced sand would likely cause damage to the surface facilities. In an offshore environment with limited workspace, crane capacity and wells with low reservoir pressures, it was decided to intervene the wells using a catenary coiled tubing (CT) vessel. The intervention required was to clean out the sand build up in the wells and install thru-tubing (TT) sand screens along the entire gravel packed screen section. Nitrified clean out was necessary due to low reservoir pressures while using a specialized jetting nozzle to optimize turbulence and lift along the deviated section. In addition, a knockout pot was utilized to filter and accommodate the large quantity of sand returned. The long sections of screens required could not be accommodated inside the PCE stack resulting in the need for the operation to be conducted as an open hole deployment using nippleless plug and fluid weight as well control barrier. A portable modular crane was also installed to assist the deployment of long screen sections prior to RIH with CT. Further challenges that needed to be addressed were the emergency measures. As the operation was to be conducted using the catenary system, the requirement for an emergency disconnect between the vessel and platform during the long cleanout operations and open hole deployment needed to be considered as a necessary contingency. Additional shear seal BOPs, and emergency deployment bars were also prepared to ensure that the operation could be conducted safely and successfully.


2021 ◽  
Author(s):  
Mark Grutters ◽  
Sameer Punnapala ◽  
Dalia Salem Abdallah ◽  
Zaharia Cristea ◽  
Hossam El Din Mohamed El Nagger ◽  
...  

Abstract Asphaltene deposition is a serious and re-occurring flow assurance problem in several of the ADNOC onshore oilfields. Fluids are intrinsically unstable with respect to asphaltene precipitation, and operating conditions are such that severe deposition occurs in the wellbore. Wells in ADNOC are generally not equipped with downhole chemical injection lines for continuous inhibition, and protection of the wells require frequent shut-in and intervention by wireline and coiled tubing to inspect and clean up. Since some of the mature fields are under EOR recovery strategies, like miscible hydrocarbon WAG and CO2 flood, which exacerbates the asphaltene precipitation and deposition problems, a more robust mitigation strategy is required. In this paper the results of two different mitigation strategies will be discussed; continuous injection of asphaltene inhibitor via a capillary line in the tubular and asphaltene inhibitor formation squeeze. Three asphaltene inhibitors from different suppliers were pre-qualified and selected for field trial. Each inhibitor was selected for a formation squeeze in both one horizontal and one vertical well, and one of the inhibitors was applied via thru-tubing capillary string. The field trials showed that continuous injection in remote wells with no real-time surveillance options (e.g. gauges, flow meters) is technically challenging. The continuous injection trial via the capillary string was stopped due to technical challenges. From the six formation squeezes four were confirmed to be effective. Three out of fours squeezes significantly extended the production cycle, from approximately 1.4 to 6 times the normal uninhibited flow period. The most successful squeezes were in the vertical wells. The results of the trial were used to model the economic benefit of formation squeeze, compared to a ‘do-nothing’ approach where the wells are subject to shut-in and cleanup once the production rates drop below a threshold value. The model clearly indicates that the squeezes applied in ADNOC Onshore are only cost-effective if it extends the normal flow period by approximately three times. However, a net gain can be achieved already if the formation squeeze extends the flow cycle by 15 to 20%, due to reduction of shut-in days required for intervention. Therefore, the results in this paper illustrate that an asphaltene inhibitor formation squeeze can be an attractive mitigation strategy, both technically and economically.


2021 ◽  
Author(s):  
Bipin Jain ◽  
Abhijeet Tambe ◽  
Dylan Waugh ◽  
Moises MunozRivera ◽  
Rianne Campbell

Abstract Several injection wells in Prudhoe Bay, Alaska exhibit sustained casing pressure (SCP) between the production tubing and the inner casing. The diagnostics on these wells have shown communication due to issues with casing leaks. Conventional cement systems have historically been used in coiled-tubing-delivered squeeze jobs to repair the leaks. However, even when these squeeze jobs are executed successfully, there is no guarantee in the short or long term that the annular communication is repaired. Many of these injector wells develop SCP in the range of 300-400 psi post-repair. It has been observed that the SCP development can reoccur immediately after annulus communication repair, or months to years after an injector well is put back on injection. Once SCP is developed the well cannot be operated further. A new generation of cement system was used to overcome the remedial challenge presented in these injector wells. This document provides the successful application of a specialized adaptive cement system conveyed to the problematic zone with the advantage of using coiled tubing equipment for optimum delivery of the remedial treatment.


2019 ◽  
Vol 32 (1) ◽  
pp. 12-19
Author(s):  
Philippe Michel ◽  
Laurie Fraticelli ◽  
Pierre Parneix ◽  
Valentin Daucourt ◽  
Olivier Farges ◽  
...  

Abstract Background Quality indicators (QI) are mandatory in French hospitals. After a decade of use, the Ministry of Health set up an expert workgroup to enhance informed decision-making regarding currently used national QI, i.e. to propose a decision of withdrawing, revising or continuing their use. We report the development of an integrated method for a comprehensive appraisal of quality/safety indicators (QI) during their life cycle, for three purposes, quality improvement, public disclosure and regulation purposes. The method was tested on 10 national QI on use for up to 10 years to identify operational issues. Methods A modified Delphi technique to select relevant criteria and a development of a mixed evaluation method by the workgroup. A ‘real-life’ test on 10 national QI. Results Twelve criteria were selected for the appraisal of QI used for regulation goals, 11 were selected for hospital improvement and seven for public disclosure. The perceived feasibility and relevance were studied including hospital workers, patients and health authorities professionals; the scientific soundness of the indicator development phase was reviewed by analyzing reference documents; the metrological performance (limited to the discriminatory power and dynamics of change during the life cycle dimensions) was analyzed on the national datasets. Applied to the 10 QI, the workgroup proposed to withdraw four of them and to modify or suspend the six others. Conclusions The value of the method was supported by the clear-cut conclusions and endorsement of the proposed decisions by the health authorities.


2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Siti Aisah Shamsuddin ◽  
Zulkifli Yusop ◽  
Shoji Noguchi

A study was conducted on the impact of forest clearance on discharge from newly established Hopea odorata plantations catchment (14.4 ha). The stands were two years old when this study commenced in year 2006 and the data collection was carried out for two years. The forested catchment (C3) was clear-cut during the preparation of the forest plantation and catchment C1 was left undisturbed. Discharge and rainfall were measured continuously for two years. The discharge measured from years 1997 to 2003 was used also to determine the water yield before and after forest clear-cut. This study showed that the plantation catchment is more responsive to storm with higher total water yield than in the forested catchment. The effect of forest clear cutting to discharge was clearly shown by the increment in the amount following the clear-cut activities and time taken for the recovery of the discharge back to its original state was almost three years. The peak discharge in C3 also was affected in which the biggest change was obtained during the forest clear-cutting period compared with during calibration and after clearing periods. This study is useful as basis for improving the existing guidelines on forest plantation establishment.


2015 ◽  
Vol 13 (32) ◽  
pp. 61-73
Author(s):  
Juan David Tarache Serrano ◽  
Germán Eduardo Martínez Barreto ◽  
Jenny Catalina González Peña ◽  
Magda Alexandra Trujillo Jiménez

This Project look for the processes simulation that take place in the oil Wells that operate the coiled tubing technique, so its workers, Company personal and anyone that wants to look these processes, can prove that consist in their cleaning methods and phase separation in these Wells, and at the same time, in what way the substances that in and out of well are controlled, show their physical features and allow that a person, without previous knowledge about the topic, may understand easily what is it injection fluid purpose by means of the C. T. in oil Wells. 


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