Solids-Free Loss-Control System Enables Efficient Coiled Tubing Workover Operations: Case Studies in Ukraine

2021 ◽  
Author(s):  
Mykhailo Pytko ◽  
Pavlo Kuchkovskyi ◽  
Ibrahim Abdellaitif ◽  
Ernesto Franco Delgado ◽  
Andriy Vyslobitsky ◽  
...  
Keyword(s):  
Control System ◽  
Gas Production ◽  
Free Fluid ◽  
Fluid Loss ◽  
Successful Implementation ◽  
Reservoir Pressure ◽  
Well Completion ◽  
Coiled Tubing ◽  
Sand Control ◽  
Loss Control

Abstract This paper describes three coiled tubing (CT) applications in depleted reservoir wells, where full circulation and precise fluid placement were achievable only by using a novel solids-free loss-control system, such as abrasive perforating applications. It also describes the preparation work, such as laboratory results and mixing procedure performed to ensure successful implementation. The analysis of Ukrainian reservoir conditions by local and global engineering teams showed that in a highly depleted well, abrasive jetting through CT was the best option to efficiently perforate the wellbore. However, this approach could lead to later impairment of the gas production if the abrasive material (sand) could not be entirely recovered. Such a risk was even higher as wells were depleted and significant losses to the formation occurred. The use of solids-free fluid-loss material that was easy to mix, pump, and remove after the operation, was, therefore, critical to the success of that approach. In Ukraine, most of the brownfields have a reservoir pressure that varies between 50% and 20% of the original reservoir pressure. This is a challenge for CT operations in general and especially for abrasive jetting, which requires full circulation to remove solids. It also complicates intervention when precise fluid placement control is required, such as spotting cement to avoid its being lost into the formation. The perforation solids-free loss-control system is a highly crosslinked Hydroxy-Ethyl Cellulose (HEC) system designed for use after perforating when high-loss situations require a low-viscosity, nondamaging, bridging agent as is normally required in sand control applications. It is supplied as gel particles that are readily dispersed in most completion brines. The particles form a low-permeability filter cake that is pliable, conforms to the formation surface, and limits fluid loss. The system produces low friction pressures, which enable its placement using CT. Introduction of that system in Ukraine allowed the full circulation of sand or cuttings to surface without inducing significant damage to the formation for first time; it was also used for balanced cement plug placements. This project was the first application of the solids-free loss-control system in combination with CT operations. It previously was used only for loss control material during the well completion phase in sand formations with the use of drilling rigs.

Malaysia's First Successful Implementation of Sand Consolidation Technology as a Primary Sand Control Method Executed during the Drilling Phase: Success Story and Lessons Learned

2021 ◽  
Author(s):  
Nadiah Kamaruddin ◽  
Nurfuzaini A Karim ◽  
M Ariff Naufal Hasmin ◽  
Sunanda Magna Bela ◽  
Latief Riyanto ◽  
...  
Keyword(s):  
Control Method ◽  
Movement Control ◽  
Lessons Learned ◽  
Successful Implementation ◽  
Success Story ◽  
Control Solution ◽  
Consolidation Process ◽  
Execution Plan ◽  
Well Completion ◽  
Sand Control

Abstract Field A is a mature hydrocarbon-producing field located in eastern Malaysia that began producing in 1968. Comprised of multistacked reservoirs at heights ranging from 4,000 to 8,000 ft, they are predominantly unconsolidated, requiring sand exclusion from the start. Most wells in this field were completed using internal gravel packing (IGP) of the main reservoir, and particularly in shallower reservoirs. With these shallower reservoirs continuously targeted as good potential candidates, identifying a sustainable sand control solution is essential. Conventional sand control methods, namely IGP, are normally a primary choice for completion; however, this method can be costly, which requires justification during challenging economic times. To combat these challenges, a sand consolidation system using resin was selected as a primary completion method, opposed to a conventional IGP system. Chemical sand consolidation treatments provide in situ sand influx control by treating the incompetent formation around the wellbore itself. The initial plan was to perform sand consolidation followed by a screenless fracturing treatment; however, upon drilling the targeted zone and observing its proximity to a water zone, fracturing was stopped. With three of eight zones in this well requiring sand control, a pinpoint solution was delivered in stages by means of a pump through with a packer system [retrievable test treat squeeze (RTTS)] at the highest possible accuracy, thus ensuring treatment placement efficiency. The zones were also distanced from one another, requiring zonal isolation (i.e., mechanical isolation, such as bridge plugs, was not an option) as treatments were deployed. While there was a major challenge in terms of mobilization planning to complete this well during the peak of a movement control order (MCO) in Malaysia, optimal operations lead to a long-term sand control solution. Well unloading and test results upon well completion provided excellent results, highlighting good production rates with zero sand production. The groundwork processes of candidate identification down to the execution of sand consolidation and temporary isolation between zones are discussed. Technology is compared in terms of resin fluid system types. Laboratory testing on the core samples illustrates how the chemical consolidation process physically manifests. This is used to substantiate the field designs, execution plan, initial results, follow-up, lessons learned, and best practices used to maximize the life of a sand-free producer well. This success story illustrates potential opportunity in using sand consolidation as a primary method in the future.

Degradable Loss Control System for Coiled Tubing Interventions

2021 ◽  
Author(s):  
Courtney Payne ◽  
Sergio Rondon Fajardo
Keyword(s):  
Control System ◽  
Low Pressure ◽  
Formation Damage ◽  
Fluid Circulation ◽  
Fracture Conductivity ◽  
Coiled Tubing ◽  
Debris Transport ◽  
Chemical Solutions ◽  
The Many ◽  
Loss Control

Abstract Coiled tubing (CT) milling and cleanout interventions depend heavily on the circulation of fluids and debris throughout a wellbore. When these interventions are performed on lateral wells which are subhydrostatic or are not able to sustain a stable column of fluid during the operation, they pose unique challenges. This is mostly due to the inability of the well to support a column of fluid, which consequently causes circulation over long distances and along narrow annular spaces to be difficult or impossible, particularly when a thief zone is present. The many consequences of poor to nonexistent fluid circulation can be severe, ranging from poor hole cleaning and formation damage to inducing a stuck pipe scenario. Over the years, many mechanical and chemical solutions have been employed to improve fluid circulation in subhydrostatic wells, but each comes with its own set of challenges and can be costly to implement. Two methods commonly used today to improve debris removal from a low-pressure wellbore include the use of nitrogen and the creation of an underbalanced condition in the wellbore by flowing formation fluids. The former is expensive, time consuming, and requires advance bottomhole assembly (BHA) planning whereas the latter can lead to significant formation damage or a reduction in fracture conductivity through the removal of proppant from the near-wellbore area. A fiber- and particulate-laden degradable loss control system (LCS) is proposed as an improvement on the current techniques used to improve circulation in subhydrostatic wells. The LCS temporarily prevents losses to the reservoir and enables the circulation of debris out of the well. The system was applied to low-pressure wells in North America to demonstrate its effectiveness in addressing the reduction or loss of circulation throughout the wellbore and improving debris transport to surface.

Extreme Challenges in FeS Scale Cleanout Operation Overcome using Temporary Isolation, High Pressure Coiled Tubing, and Tailored Fluid Systems

2014 ◽  
Author(s):  
Mustafa Buali ◽  
Noel Ginest ◽  
Jairo Leal ◽  
Oscar Sambo ◽  
Alejandro Chacon ◽  
...  
Keyword(s):  
Safety Concern ◽  
Gas Production ◽  
Reservoir Pressure ◽  
Chemical Solution ◽  
Reservoir Temperature ◽  
Coiled Tubing ◽  
Fluid Systems ◽  
Operational Envelope ◽  
Fluid Losses ◽  
Scale Deposition

Abstract The carbonate gas producing zones of the Ghawar field have been impacted by extensive FeS scale deposition, reducing overall gas production and significantly increasing risks of well interventions. Previous remediation included the use of workover rigs, which can be costly because of the time necessary for workovers and lost production. H2S levels (2 to 5%) found in the reservoir also contribute to higher costs and risks when using workover rigs. A chemical solution was also considered, but the FeS could not be 100% dissolved with HCl and the chemical reaction generated large amounts of H2S in addition to existing high levels of H2S in the reservoir. This poses a safety concern with the returns at surface along with potential corrosion of the coiled tubing (CT) and completion. Therefore, the safest and most economical method was deemed to be mechanical descaling with CT. This paper discusses two wells where mechanical descaling was applied using CT. Each well involved four major challenges that included low reservoir pressure, increased reservoir temperature, horizontal openhole completion, and scale with high specific gravity (3.7 to 4.3). The low reservoir pressure required pay zone isolation to allow for returns to circulate out the heavy scale and to minimize fluid losses to the formation. The fact that the wells had long, openhole sections created another challenge for isolation and cleanout. With a bottomhole temperature (BHT) as high as to 310°F, the operational envelope of temporary chemical packers in combination with loss circulation materials (LCMs) to isolate the openhole section had to be expanded. Following mechanical descaling with CT, the final challenge discussed in this paper is the process to clean out the LCM in the horizontal openhole and bring the well back to maximum gas production using pinpoint stimulation techniques.

Well Design and Successful Field Installation of Openhole Sand Control Completions with Acid Stimulation in a Highly Deviated Well in Vietnam

2016 ◽  
Author(s):  
Hung Vu ◽  
Son Tran ◽  
Trang Nguyen ◽  
Bharathwaj Kannan ◽  
Khoa Tran ◽  
...  
Keyword(s):  
Control Device ◽  
Production Performance ◽  
Fluid Loss ◽  
Horizontal Section ◽  
Well Completion ◽  
Well Design ◽  
Mud Cake ◽  
Sand Control ◽  
Open Hole ◽  
Oil Rim

ABSTRACT Application of openhole sand control technology is becoming mandatory in the field, particularly with the given uncertainty in geomechanics, challenges to wellbore integrity while drilling, and sand production during the life of the well. The completion equipment readiness and success of the installation can be challenging in the event of extending the horizontal section to accommodate geological heterogeneity and maximizing well productivity. This paper discusses operational excellence recorded in Well A, in the Thang Long Field, offshore Vietnam, from well design perspectives ensuring maximum reservoir contact to outcome of well completion. The well was targeted in the Oligocene reservoir, a thin oil rim with large gas cap overlay, and required drilling and completion for 1126 m horizontal length of 8 1/2-in. open hole. The completion design included multiple swellable packers for isolation of unwanted zones, 6 5/8-in. basepipe sand screens for the production zones, and a fluid loss control device to help prevent undesirable losses. Several torque and drag simulations were performed to help predict potential threats that could be encountered during completion string deployment or during space out of the inner wash pipe string. One apparent challenge of this completion design was to deploy the lower completion string to total depth (TD) per stringent reservoir requirements, resulting in an approximate 1126 m length of the string in the horizontal section. Another task was to facilitate manipulating 1130 m of wash pipe inside the completion string to locate the seal assemblies accurately at the corresponding seal bore extension positions for effective acidizing treatment. Although these were long sections of completion string and wash pipe, the quality of acidizing stimulation to effectively remove mud cake should not be compromised to ensure positive production rates. During operations, the completion string was run to target depth without any issue, and the wash pipe was spaced out and manipulated correctly. These operations subsequently led to a successful acidizing treatment and the proper closure of the flapper type fluid loss device. The completion design and operation were concluded successfully, significantly contributing to field production performance to date. The novelty of the completion design and installation is the ability to deploy an 1126-m lower completion in long, highly deviated and horizontal openhole section coupled with acid stimulation in reasonable time and as per plan.

Achieving Injectivity Optimization and Zonal Rates Allocation through Multi-Zone Intelligent Completion Technology – A Field B Case Study from Offshore Malaysia

2021 ◽  
Author(s):  
Fuziana Tusimin ◽  
Latief Riyanto ◽  
Nurul Aula A'akif Fadzil ◽  
Nur Syazana Sadan ◽  
Asba Mazidah Abu Bakar ◽  
...  
Keyword(s):  
Real Time ◽  
Pressure Support ◽  
Water Injection ◽  
Injection Rate ◽  
Fluid Distribution ◽  
Successful Implementation ◽  
Reservoir Pressure ◽  
Well Completion ◽  
Ic Technology

Abstract Properly distributing injected fluid to provide injection conformance and reservoir pressure support into the respective zones of interest in mature fields can be challenging. This challenge, with injection fluid distribution, is typically encountered in fields with high contrast in permeability, reservoir pressure, and injectivity indexes among individual zones. Deployment of intelligent completion (IC) technology to address this challenge has rapidly increased, especially in multi-zone water injector wells, due to its capabilities for real-time reservoir monitoring and control of the fluid injected into multiple zones without requiring well interventions. This paper presents a case study of successful installation of IC technology in two water injector wells in Field B offshore Sarawak. The main objective of the IC implementation is to provide an efficient water-injection method for pressure support to the nearby oil producers and counteract the gas expansion through water injection at the flank area. Water injection implementation using the IC approach can further develop the oil rims and improve oil recovery in the particular reservoir to extend the field's production life. The custom tailored inflow control valve (ICV) design is robust enough to provide control of desired zonal injection rates. Each well was installed with two sets of ICVs to control the injection rate for each dedicated zone as well as a real-time permanent downhole gauge (PDG) to monitor the pressure drop across the ICV for zonal rates allocation / analysis. Apart from conceptual and detailed engineering study of the applied IC technology, proper downhole equipment selection and integration with surface facilities are also crucial to ensure successful implementation of the IC system as a holistic solution to achieve the injection objective. Post well completion installation, a water injectivity test was performed in both the selective and commingle injection modes. During selective injection testing, different positions of the ICV were manipulated and the water injection rate was monitored. This testing approach was performed for each ICV in the well. Post selective injection testing, commingle testing was conducted at the base 9,000 bwpd and maximum injection target of 18,000 bwpd, in which the testing was successfully executed to achieve the maximum well target injection rate. This paper shall discuss the reservoir management strategy through deployment of the water injectors, conceptual well completion design, and multi-zone injectivity requirements. Details such as ICV design using pre-drill and post-drill information, final well completion strategy, pre-installation preparation, installation optimization, execution of the IC deployment, injectivity test procedure, and results are discussed as well.

Buzios Presalt Wells: Delivering Intelligent Completion In Ultra-Deepwater Carbonate Reservoirs

2021 ◽  
Author(s):  
Eduardo Schnitzler ◽  
Luciano Ferreira Gonçalez ◽  
Roger Savoldi Roman ◽  
Marcello Marques ◽  
Fábio Rosas Gutterres ◽  
...  
Keyword(s):  
Fluid Loss ◽  
High Productivity ◽  
Well Completion ◽  
Well Design ◽  
Managed Pressure Drilling ◽  
Engineering Team ◽  
Open Hole ◽  
Improved Performance ◽  
Loss Control ◽  
Fluid Losses

Abstract This paper describes the challenges faced on the deployment of intelligent well completion (IWC) systems in some of the wells built in Buzios field, mostly related to heavy fluid losses that occurred during the well construction. It also presents the solutions used to overcome them. This kind of event affects not only drilling and casing cementing operations, but may also prevent a safe and efficient installation of the completion system as initially designed. The IWC design typically used in Brazilian pre-salt areas comprises cased hole wells. Perforation operations must be performed before installing the integral completion system, as it does not include a separation between upper and lower completion. Therefore, the reservoir remains communicated to the wellbore during the whole completion installation process, frequently requiring prior fluid loss control as to allow safe deployment. Rock characteristics found in this field make it difficult to effectively control losses in some of the wells, requiring the use of different well construction practices that led to the development of some new well designs. The well engineering team developed a new well concept, where a separated lower completion system is installed in open hole, delivering temporary reservoir isolation. This new well architecture not only delivers reduced drilling and completion duration and costs, but also provides the IWC features in wells with major fluid losses. This is possible by the use of multiple managed pressure drilling (MPD) techniques when required, which were considered since the initial design phase. Safe and effective construction of some wells in pre-salt fields was considered not feasible before the adoption of MPD solutions, both for drilling and completions. Other important aspects considered on the new well design are the large thickness and high productivity of Buzios field reservoirs, as well as the need of some flexibility to deal with uncertainties. Finally, the new completion project was also designed to improve performance and safety on future challenging heavy workover interventions. The well construction area has gradually obtained improved performance in Buzios field with the adoption of the new practices and well design presented in this paper. The new solutions developed for Buzios field have set a new drilling and completion philosophy for pre-salt wells, setting the grounds for future projects. The improved performance is essential to keep these deepwater projects competitive, especially in challenging oil price scenarios. One of the groundbreaking solutions used is the possibility of installing the lower completion using managed pressure drilling techniques.

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