bluuebunny/crossref_metadata_2025_split huggingface dataset:
Overcoming Hole Instability in Highly Deviated Wells in the Kafr El Sheikh Shale, Offshore Mediterranean, Egypt
Authors: Kholaif Yasser , Elmaghraby Mahmoud , Nago Annick , Embry Jean-Michel , Basu Pramit , Perumalla Satya , El-Said Mohamed M. , ElMenshawy Ali , Baghdadi Ahmed 
Published: May 2021

Abstract
Drilling challenges in offshore Nile Delta have been largely documented in the literature. Operators are often confronted with drilling problems related to shale swelling, cavings, tight holes in combination with increased risks of lost circulation in some of the highly depleted formations. The Kafr El Sheikh shale in particular, has been linked to many instances of wellbore instability, due to its mineralogical composition (estimated to be mostly smectite, &gt;70%). From offset well drilling experience, it could also be noticed that insufficient mud weight was often used to drill through the Kafr El Sheikh Shale, causing wellbore failure in shear due to lack of support of the wellbore wall. In the past, multiple mud weight designs have been implemented relying solely on pore pressure as lower bound of the mud window. With the increased use of geomechanics, it has been demonstrated that the lower bound should be taken as the maximum of the pore pressure and borehole collapse pressure, thus accounting for the effects of formation pressure, horizontal and vertical stresses, rock properties as well as wellbore trajectory. It has been proven that slight overpressure is often encountered halfway through the Kafr El Sheikh formation, which would typically result in slightly higher borehole collapse pressures. In the study fields, the operator expressed interest in drilling highly deviated wells (&gt; 60-70 degrees). This raised concerns for increased drilling challenges, especially in the Kafr El Sheikh.
A comprehensive and systematic risk assessment, design of a fit-for-purpose solution and its implementation during drilling took place in the fields of interest. Offset well data analytics from the subject fields supported a holistic evaluation of drilling risks associated with the Kafr El Sheikh, providing good understanding of stress sensitivity on deviation, azimuth and lithology. Upon building a robust geomechanical model, calibrated against offset well drilling experience, pre-drill mud weight and drilling practices recommendations were provided to optimize the drilling program. Near real-time geomechanical monitoring was implemented which helped to manage the model uncertainties.
The implementation of a holistic risk assessment, including geomechanical recommendations and near real-time geomechanical monitoring, was effective to lead the drilling campaign successfully. As a result, three high angle wells (&gt; 60-70 degrees) were drilled through the challenging Kafr El Sheikh formation without any hole instability. An integrated risk assessment of hole instability, managed in stages (pre-drill and during drilling), has helped to understand and simulate the behaviors of the formation. Proactive decisions have established a controlled drilling environment for successful operations.
Successful Application of Managed Pressure Drilling MPD Technology to Reach TD in a Narrow Margin HPHT Well in the North Sea – A Case History
Authors: Kamal Babar , Stoian Emil , MacFarlane Graeme 
Published: May 2021

Abstract
This paper reviews the recently concluded successful application of a Managed Pressure Drilling (MPD) system on a High-Pressure High-Temperature (HPHT) well with Narrow Mud Weight Window (NMWW) in the UK sector in the Central North Sea. Well-A was drilled with the Constant Bottom Hole Pressure (CBHP) version of MPD with a mud weight statically underbalanced and dynamically close to formation pore pressure.
Whilst drilling the 12-1/2" section of the well with statically under-balanced mud weight, to minimize the overbalance across the open hole, an influx was detected by the MPD system as a result of drilling into a pressure ramp. The MPD system allowed surface back pressure to be applied and the primary barrier of the well re-established, resulting in a minimal influx volume of 0.06 m3 and the ability to circulate the influx out by keeping the Stand Pipe Pressure (SPP) constant while adjusting Surface Back Pressure (SBP) through the MPD chokes in less than 4 hours with a single circulation.
After reaching the 12-1/2" section TD, only ~0.025sg (175 psi) Equivalent Mud Weight (EMW) window was available to displace the well and pull out of hole (POOH) the bottom hole assembly (BHA) therefore, 3 × LCM pills of different concentrations were pumped and squeezed into the formation with SBP to enhance the NMWW to 0.035sg EMW (245 psi) deemed necessary to kill the well and retrieve BHA. MPD allowed efficient cement squeeze operations to be performed in order to cement the fractured/weak zones which sufficiently strengthened the well bore to continue drilling. A series of Dynamic Pore Pressure and Formation Integrity Tests (DPPT and DFIT) were performed to evaluate the formation strength post remedial work and to define the updated MMW.
Despite the challenges, the MPD system enabled the delivery of a conventionally un-drillable well to target depth (TD) without any unplanned increase/decrease in mud weight or any costly contingency architecture operations, whilst decreasing the amount of NPT (Non Productive Time) and ILT (Invisible Lost Time) incurred.
This paper discusses the planning, design, and execution of MPD operations on the Infill Well-A, the results achieved, and lessons learned that recommend using the technology both as an enabler and performance enhancer.
Offshore Installation of Rigless Shuttle ESP
Authors: Obeid Ahmad Fayyad , Bespalov Eugene , Sanghavi Dharam , Almasri Ahmad , Magri Jose , Al Hammadi Majid Ismail , Al Marzooqi A. M. , Yoshimoto Kazuhito Kazumi , Yamashita Hajime , Al Zaabi Ali Yousef 
Published: May 2021

Abstract
Electric submersible pumps (ESPs) used as an artificial lift method have a relatively short life span despite the industry's efforts to improve reliability. The resulting economic impact realized in workover costs and production loss is substantial. This has driven efforts toward design change by introducing retrievable ESP independent of the completion string and hence extending ESP wells’ life cycle. This paper covers the company's first installation of a rigless shuttle ESP system, including a customized completion design and special deployment procedures.
A comprehensive approach was taken to deploy this technology, from procurement to installation, in a detailed process. It started with acquiring reservoir data and setting up matching specifications for the required equipment in order to issue a competitive tender. Following technical evaluation of tender submissions, the most suitable technology was selected for the field trial. The completion design was then customized to accommodate the new technology without jeopardizing well integrity. Fit-for-purpose well barriers were incorporated in the completion design because conventional barriers were not applicable. Detailed running procedures were produced from dedicated workshops and risk assessment reviews. Project execution was closely monitored and firmly controlled.
The company has accomplished the first successful offshore deployment of the shuttle ESP system in the MENA region. The system was deployed using tailored procedures for installation and comprehensive testing while ensuring compliance with well barrier requirements. Following successful deployment, the ESP performance was positively tested. Part of the project validation requirement was a rigless retrieval and redeployment the ESP system. The ESP retrieval process was challenging due to unexpected tar or asphaltene material encountered above the ESP. However, contingency retrieval procedures were promptly amended with detailed steps to overcome this challenge, which led to successful retrieval and redeployment of the ESP without NPT. This success is paving the way for a major change in the company's field development strategies by considering rigless, replaceable ESP systems instead of the conventional ESPs.
This paper sheds the light on a new advancement in completion technology that has a strong potential to prevail for ESP-lifted wells in the future. The focus of the paper is on the design and execution parts, as well as installation and post-completion operations while maintaining sufficient well barriers―the challenging aspect that appears to be slowing down the wider use of this technology as a replacement of conventional ESP completions.
Developing New Generation of Environmentally Friendly Nano Based Low Saline Water-Based Drilling Fluid
Authors: Kalhor Mohammadi Mojtaba , Taraghikhah Shervin , Karimi Rad Mohammad Saeed , Tahmasbi Nowtaraki Koroush 
Published: May 2021

Abstract
Developing high-performance environmentally friendly drilling fluids is always a requirement by oil and gas operators to reduce the waste management associated cost with the drilling fluid treatment and disposal. Conventional water-based drilling fluid is formulated with the brine-based polymer which consists of sodium and potassium chloride salts to improve the performance of the polymer and also providing clay inhibition in reactive clay and shale. This paper describes the development of nanotechnology-based drilling fluid to replace salt from the conventional application.
Nano Based Low Saline Water Based Mud (NBLS-WBM) was formulated and developed based on laboratory experiments. Different nano additives with different concentrations were evaluated and the optimum concentration was selected to reduce the sodium and potassium chloride salts concentration to almost zero. The rheological properties and fluid loss were measured according to the API standard before and after hot rolling. Also, HPHT fluid loss, lubricity, and shale inhibition were evaluated. All the results were compared with sodium salt-saturated and potassium-based polymer muds.
Laboratory evaluation of NBLS-WBM indicated that sodium salt concentration can be reduced considerably up to 5% W/V and potassium chloride can be eliminated by adding 1% W/W of nano additive. The rheological properties including plastic viscosity and yield point were constant and stable after hot rolling 16 hours at 250 °F. Also, Clay inhibition improved significantly up to 95% recovery comparing with conventional water-based polymer mud.
Although the application of nanotechnology to improve the performance of conventional water-based drilling fluid was studied by many researchers, it is the novelty of this research to reduce the salt concentration and remove it to develop the new generation of salt-free water-based drilling fluid with economical consideration and lower environmental impact.
A Systematic Approach to De-Risk and Improve Shale Gas Horizontal Well Drilling
Authors: Gao Xiang , Zeng Jiaxin , Xie Jiajun , Tang Liang , Li Wenzhe , Gui Feng , Ghosh Amitava , Ong See Hong , Huang Xingning , Deng Lichuan 
Published: May 2021

Abstract
Horizontal well drilling contribute to a dramatic increase of shale gas production in unconventional reservoirs. However, the drilling is also risky and challenging with different types of drilling problems often encountered including stuck pipes, inflows, losses and pack-offs, etc. To reduce shale-gas development costs, shale gas operators are faced with finding effective solutions to minimize drilling risks and improve drilling efficiency. A holistic workflow, which can be divided into three steps: pre-drilled modelling and assessment, real-time monitoring, and post-drilled validation, is proposed. Based on the pre-drilled geomechanical modeling, mud weights, mud formulations and casing setting depths are optimized to ensure wellbore stability during the drilling process. Real-time operations involve monitoring drilling parameters and cavings characteristics (shape and volume), and providing updated recommendations for field drilling engineers to mitigate and reduce borehole instability related problems. During the post-drilled stage, the updated geomechanical model will be used for optimizing the drilling designs of upcoming wells. With geomechanics as foundation, a systematic workflow was developed to provide integrated solutions by using multiple technologies and services to reduce serious wellbore instability caused by abnormal formation pressures, wellbore collapse and other complex drilling problems. The implementation of the systematic and holistic workflow has proven to be extremely successful in supporting the drilling of shale gas wells in China. The integrated approach, which was applied in a Changning shale gas block in Sichuan Basin for the first time in March 2019, recorded an improvement in ROP by 111.2% and a reduction in mud losses by 89.9% compared with an offset well without the risk mitigation strategy applied in the same pad. The geomechanics-based approach provides a convenient and effective means to assist field engineers in mud weight optimization, drilling risk assessments, and horizontal well drilling performance evaluation. The approach can also be extended to reduce potential drilling risks and improve wellbore stability, all of which contributes to reducing drilling costs and optimizing subsequent massive hydraulic fracturing jobs.
The Theory and the Practical Validation of the Fluid Level Position in the Annulus During Lost Circulation
Authors: Ruzhnikov Alexey , Echevarria Edgar 
Published: May 2021

Abstract
Carbonate formations around the world and specifically in a Middle East are prone to have total losses while drilling. And the nature of the losses often related to the highly fractured formations of the pay zone. When such fracture(s) is crossed by the wellbore the lost circulation initiated and led to a drilling without a return to a surface.
To avoid undesired well control event or wellbore instability and to maintain the constant bottom hole pressure the mud cap drilling strategy often used as a preventative measure. The mud cap can be either the continuous or based on some volume or time interval, depends on the local practices or the policy of an operator. The mud cap flow rate as well as mud cap mud weight are often based on the best practices, not supported by an engineering study.
To understand the behavior of the drilling fluid level in the annulus while drilling with total losses the drilling bottom hole assembly equipped with annular pressure while drilling tool was used. As the drilling required to use the continuous mud cap, then the specific guideline was developed on measurement of the bottom hole pressure and further conversion of it to the fluid level.
The study was performed across pay zone with one or several loss circulation zones identified. As the result it was confirmed that the used mud cap flow rate had minor to none effect on the fluid level position in the annulus and that the bottom hole pressure remained the same. It showed as well that different loss zones are behaving in a different way, what can be considered as a factor affecting their ability to be sealed.
The obtained knowledge and the information should help to understand better the loss circulation behavior as well be an important step toward development of the product which may cure the losses in high fractured carbonate formations. The results of the study can be implemented in any other project or a field.
All-Electric Intelligent Completion System: Evolution of Smart Completion
Authors: Samuel Orient Balbir , Chandrakant Ashvin Avalani , Salleh Fairus Azwardy , Jamil Ahsan , Ibrahim Zulkifli , Ivey Alan 
Published: May 2021

Abstract
Field D is a mature offshore field located in East Malaysia. A geologically complex field having multiple-stacked reservoirs with lateral and vertical faulted compartments & uncertainty in reservoir connectivity posed a great challenge to improve recovery from the field. Severe pressure depletion below bubble point and unconstrained production from gas cap had contributed to premature shut-ins of more than 50% of strings. As of Dec 2019, the field has produced at a RF less than 20%. Initial wells design consisted of conventional dual strings & straddle packers with sliding sleeves (SSD). Field development team was challenged for a revamp on completion design to enhance economic life of the depleting field.
In 2015, as part of Phase-1 development campaign, nine wells including four water injectors were completed initiating secondary recovery through water flood. An approach of Smart completion comprising of permanent downhole monitoring system (PDHMS) and hydraulic controlled downhole chokes or commonly known as flow control valve (FCV) was adopted in all the wells in order to optimize recovery from the field and step towards intervention-less solutions. Seeing the benefits of intelligent completion in Phase-1, Phase-2, drilled and completed in 2019 – 2020 has been equipped with new technology "All-electric Intelligent Completion System" in 4 out of 8 oil producers. The new design addresses the reservoir complexity, formation pressure and production challenges and substantial cost optimization, phasing out the load of high OPEX to CAPEX.
Installation of "All-electric Intelligent Completion System" has proven to be an efficient system compared to hydraulic smart completions system. It requires 50% to 75% less installation time per zone and downhole FCV shifting time is less than five minutes compared to several hours full cycle for hydraulic system. The new system has capability to complete up to 27 zones per well with single cable. It gave more options and flexibility in order to selectively complete more zones compared to hydraulic FCVs which requires individual control line for each zone. Future behind casing opportunities (BCO) have been addressed upfront, saving millions of future investment on rig-less intervention. In addition to that, non-associated gas (NAG) zones have been completed to initiate in-situ gaslift as and when required avoiding the dependency on aging gaslift facility.
The scope of the paper is to show case the well design evolution during Field D development and highlight on how smart completion has evolved from original dual completion to hydraulic smart and recently to electric smart system, how it has contributed to cost and production optimization during installation and production life and also support the gradual digitalization of the Field D. In the end it demonstrates the optimized completion design to enhance the overall economic life of the depleting field.
Probabilistic Estimation of Water Flood Requirement to Control Flow Behind the Casing on Offshore Platforms
Authors: Haghshenas Arash , Luengo Emilio , Bansal Yogesh , Mijares Geraldo 
Published: May 2021

Abstract
Recently, flood kill applications have been evaluated to cure blowouts due to gas migration from behind the casing while keeping the well integrity intact for further production. Traditionally, deterministic evaluations are used in planning these operations, ignoring the uncertainties in the characteristics of the gas sources behind the casing. This work focuses on using reservoir simulation-based workflow to evaluate the uncertainty providing probabilistic operating conditions to control the gas rates coming from behind the casing. The results of the simulations are combined to provide general guidelines for performing an effective flood kill operation. The studied parameters are divided in different categories based on their influence/impact on the effective kill. For example, the relationship between the best relief well position and reservoir permeability and anisotropy are studied, and the guidelines for the definition of the best location is identified. Based on the results of the analysis, the optimum required proximity of the wells can be determined. The analysis identifies the main factors for a successful flood kill operation. The situations where flood kill could be beneficial are identified and the success rate could be evaluated. This paper presents a methodology and guidelines for the design of an effective flood kill application. This methodology will help in positioning of the relief well and provide required control mechanisms to increase the chances of a successful operation. The methodology also provides insight on the required operating parameters, such as pump rates and total volume to be injected, for the operation to be successful. In addition, the developed workflow can be updated as more information is gathered while drilling the relief well. This will help in improving the chances of a flood-kill operation while providing tighter controls on the operational conditions.
Impact of Multi-Branched Ionic Liquid on Shale Swelling and Hydration for High Temperature Drilling Applications
Authors: Khan Rizwan Ahmed , Ahmad Hafiz Mudaser , Murtaza Mobeen , Abdulraheem Abdulazeez , Kamal Muhammad Shahzad , Mahmoud Mohamed 
Published: May 2021

Abstract
Shale swelling and hydration during the drilling operation have adverse effects on the stability of a wellbore. Hydrophilic interactions of shale results in swelling and disintegration of the shale formation. This paper discusses wettability changes and hydration characteristics of shale to improve the wellbore stability. The use of multibranched ionic liquid as drilling fluid for high temperature applications was investigated.
The novel multibranched ionic liquid (Trihexyltetradecyl phosphonium bis (2,4,4-trimethyl pentyl) phosphinate, denoted as Tpb-P) water-based drilling fluid was prepared by mixing different concentrations of ionic liquid and other additives such as filtration controller, rheological modifier, and pH controller. The wettability of bentonite powder was determined using a contact angle in the presence of various concentrations of ionic liquids. Several other experimental techniques, such as linear swelling, hot rolling recovery, and bentonite swell index, were used to examine the inhibition performance of ionic liquid. The rheology and filtration properties of ionic liquid-based drilling fluid were also examined.
Various concentrations of multibranched ionic liquid were used to formulate the drilling fluids ranging from (0.1 to 0.5 wt.%), and their performances were compared with the base drilling fluid prepared without ionic liquid. The hydrophobicity of the shale surface was determined by measuring the contact angle, and results showed that drilling fluid having 0.1 wt.% concentration of ionic liquid has a maximum contact angle indicating the highly hydrophobic shale surface. The hot rolling shale recovery experiment was conducted at 150°F, and it was observed that adding ionic liquid improved the shale recovery (24.4%) compared to the base fluid recovery (12.8%). The linear swelling was evaluated over the time of 24 hours, and the least swelling of bentonite was noticed with 0.1 wt.% ionic liquid (98.1%) compared to linear swelling in deionized water (125%). The results suggested that the ionic liquid in the drilling fluid chemically interacted with the clay surface and reduced the hydrophilicity of clay, which restricts the exchange of water onto the clay surface.