bluuebunny/crossref_metadata_2025_split huggingface dataset:
Coiled Tubing Underbalanced Drilling Implementation Planning in Tight Gas Reservoirs (First Time in ADNOC Group of Companies)
Authors: Zain Fawad , Deshmukh Rohit Villas , Al Mteiri Nama Ali , Baslaib Mohamed Ahmed , Osama Mohamed , Elshehat Ayman , Bin Sumaida Ali Sulaiman , Abdulsalam Fouad , Ahmed Mubashir , Soliman Tarek , Mantilla Alfonso 
Published: October 2022

Abstract
In order to maximize the recovery from Low permeability tight reservoirs, several treatments are possible to remove post (overbalanced) drilling damage; however, the desired well performance has not been achieved. As an alternative Under Balanced Coiled Tubing Drilling implementation has been considered for ADNOC Onshore gas wells as pilot trial in attempt to counteract the invasion of drilling mud into the formation.
The recovery of (low perm) tight reservoirs is always affected by overbalanced drilling. As an alternative solution to stimulation jobs to remove the damage (skin), which has been used widely but still not getting the desired results, Under Balanced Drilling is one of the solutions to not impair the formation while drilling thus providing clean flow area/ connection. However, considering H2S contents and limitation of Well Control Barriers for Gas wells, the conventional Under Balanced Drilling is not suitable. Considering the current challenge in sour gas environment, Coiled Tubing Underbalanced Drilling is considered for pilot implementation of 3 wells in ADNOC Onshore; in which drilling of reservoir section is carried out after running the completion and continuous underbalance conditions are maintained.
This CT-UBD implementation planning included detailed planning /feasibility study and well design finalization including updating completion design. Accordingly, the well was tied-in to facilities before starting the implementation. This also included developing detailed engineering design and complete project planning including but not limited to HazID, HazOp, Engineering design, procedures finalization, contingency planning and detailed execution program.
This paper will examine a detailed approach used for planning the CT-UBD job for the first time in ADNOC Group of companies covering subsurface, operational and HSE aspects that impacted positively on the project success.
Research and Successful Field Application of Nanosilica System for Gas Shutoff in Horizontal Well
Authors: Almohsin Ayman , Hashem Hassan , Sadah Ali , Mahtani Mesfer 
Published: October 2022

Abstract
Innovative and cost-effective gas shutoff technologies are required to improve the oil recovery and avoid the problems associated with the unwanted gas production. A novel strong and stable material with controlled gelation time was developed to isolate gas production zones over a wide range of parameters including the temperature, pressure, injectivity duration, and flow rate.
This paper details the nanosilica for gas shutoff from laboratory development to successful field treatment. The nanosilica technology is composed of modified nanosilica and an activator which is used to trigger the viscosity of the system. The gelation time and gel strength of the nanosilica in presence of different concentrations of the activator have been investigated. In addition, the impact of the temperature on the gelation time was examined. The gas shutoff field treatment was designed to prevent the gas production from horizontal oil well based on the results obtained in the laboratory at comparable conditions.
Laboratory results revealed that the two-component system namely the modified nanosilica and the activator exhibits low viscosity i.e. 6 cp prior to the exposure to high temperature. Once the temperature is increased to certain values, the viscosity of the mixture will increase depending on the concentration of the activator such that the start point of colloid-gelling ranged from a few minutes to several hours at a given temperature. Thus, this fluid system can be placed as a single phase, low-viscosity solution into the targeted formation zones and subsequently gelled inside the formation resulting in complete plugging. For the job design, production logging tools were run on the E-coil string to detect the gas source and measure the bottomhole temperature required for the formulation of gas shutoff nanosilica, and also to measure the injection pressure to monitor the injectivity. The objective of this job is to isolate the 980 ft. of stand-alone screens. Results unveiled the great potential of nanosilica as a gas-shutoff approach to mitigate gas intrusion with a sustainable 65% gas reduction compared to pre-treatment results.
The new trend of using eco-friendly and nanoscale particles in gas control applications is a breakthrough in the oil industry. Laboratory results and field data revealed that the nanosilica for gas shutoff was effective over a wide range of parameters including the temperature, pressure and permeability.
Recent Advancements in Viscoelastic Polymer Flooding EOR Applications in Carbonates and Sandstones
Authors: Zeynalli Mursal , Alfazazi Umar , Mushtaq Muhamad , W. Al-Shalabi Emad , AlAmeri Waleed 
Published: October 2022

AbstractPolymer flooding is a well-established chemical enhanced oil recovery (CEOR) technique that effectively improves oil recovery after waterflooding. Due to a large number of studies conducted in this area and extensive field data availability, this technique has gained solid practical and theoretical knowledge. Conventionally, the polymer injection is believed to increase volumetric sweep efficiency by producing movable oil that is remained unswept after waterflooding. Nevertheless, studies demonstrated that specific viscoelastic polymers might also mobilize residual oil and improve microscopic displacement efficiency, in addition to macroscopic sweep efficiency.Although polymer flooding is an extensively applied CEOR technique in sandstones, its applicability in carbonates is still limited. This is related to the prevailing complicated conditions in carbonates including mixed-to-oil wettability nature, high heterogeneity with low permeability, and harsh conditions of high temperatures (above 85°C), high salinity (above 100,000 ppm), and high hardness (above 1,000 ppm). Recently, new polymers have been developed to overcome the challenges of harsh conditions in carbonates. These novel polymers incorporate specific monomers that protect the polymer from thermal and chemical degradations. However, the viscoelasticity of these synthetic polymers and their effect on oil mobilization are not yet comprehended and requires further investigation and research.In this paper, we review the recent studies conducted on viscoelastic polymer flooding in sandstones and carbonates. The article describes viscoelastic polymer recovery mechanisms, polymer viscoelastic properties and the factors controlling them, and the effect of viscoelastic polymers on residual oil mobilization. This study also provides insights into the challenges faced during viscoelastic polymer flooding operations as well as field applications in sandstone and carbonate reservoirs.
Lessons Learnt from First Time Coiled Tubing Underbalanced Drilling Implementation in Adnoc Group of Companies
Authors: Abd EL Meguid Mohamed Osama , EL Shahat Ayman , Bin Sumaida Ali Sulaiman , Al Mutawa Ahmed Abdulla , Saleh Abdalla Saleh , Almazrouei Saeed Mohamed , Mantilla Alfonso , Yousfi Fawad Zain , Baslaib Mohamed Ahmed , Al Ali Abdulrahman Hasan , Al Hosani Mariam Ahmed , Al Bairaq Ahmed Mohamed , Mohamed Ihab Nabil , Ojha Aditya , Alawadhi Fatima Omar , Solaiman Tarek , Almteiri Nama , Bernadi Bondan , Rangel Pedro , Basha Maged , Cui Shuai , Jumagaliyev Yerlan , Rennox John 
Published: October 2022

Abstract
ADNOC Onshore initiated a pilot implementation of Under Balanced Coiled Tubing Drilling technologies for Gas Reservoirs with this being the first time in the ADNOC Group of Companies. Detailed planning was carried out for this project implementation and the onward optimization for the 3rd well based on lessons learnt was carried out.
This 3 well pilot Underbalanced Coiled Tubing Drilling, UBCTD, pilot campaign involves the sidetracking from a pre-drilled 6" hole and then drilling 3-¾" laterals with the laterals drilled in a carbonate gas reservoir utilizing UBCTD technology and methods with these being applied to eliminate formation damage, enhance production, and improve drilling performance.
A Unique High Temperature, Low Rheology Divalent Brine-Based Reservoir Drilling Fluid Improved Horizontal Drilling Performance in Hard Sandstone Formation
Authors: Kerkhoff Erik , Ismail Ahmed , Butcher Jacques , Huestis Matthew , Rekieh Aubyii 
Published: October 2022

Abstract
This paper describes how a dual function synthetic polymer (DFSP) additive was key to formulating a unique high temperature divalent brine-based reservoir drilling fluid (HT-DB-RDF), deployed to drill a horizontal slim hole interval through a hard sandstone formation. To efficiently drill this horizontal section the HT-DB-RDF was developed with the intent to improve drilling performance. The main parameter targeted for improvement was the rate of penetration (ROP) without compromising wellbore quality or increasing the risk of common drilling problems such as hole cleaning, wellbore integrity, drilling torque and differential sticking.
During the well planning phase, different fluid formulations, qualification approaches and field deployments were reviewed from global experience. In certain geologically similar applications, improved ROPs had been achieved using low solids and (in some instances) clear fluid systems. The most notable difference between the planned application and offset experience was the bottom hole temperature (155°C) and fluid density that was required (1.32 SG). A fluids design framework was developed from the offset well analysis and available pre-drill data. Reservoir Drilling Fluid technologies were evaluated, and laboratory work was performed to develop the system. Detailed hydraulics modelling was performed during the planning phase to confirm that the HT-DB-RDF could deliver the required performance under the planned conditions. High flow rates and low rheology were required for turbulent flow in the annulus to transport cuttings, maximizing hydraulic power to the downhole tools and drill bit and enhancing ROP.
The success of the HT-DB-RDF was assessed during execution of the well. Downhole fluid properties were used to model drill string hydraulics, equivalent circulating density (ECD) and hole cleaning ahead of the bit under the drilling conditions. Outcomes were compared to pressure-while-drilling data at the rig site to detect trends indicating poor hole cleaning. The results showed a maximum 0.01 SG variance between modelled and measured ECD, and smooth trips illustrated a clean and stable wellbore throughout. Non-fluid related operational issues resulted in a longer time to drill the interval and extended static periods during trips. The HT-DB-RDF exhibited resilience during elevated downhole temperatures. The average ROP recorded during drilling was eight times higher than the previous ROP achieved drilling horizontal offset wells.
The key technology that enabled fluid development and execution of the well was the DFSP that delivered both high temperature fluid loss control and hole cleaning capabilities. The DFSP features strongly bonded chemical linkages and cross-linked chains which achieve exceptional performance in divalent brine, facilitating high fluid densities with low solids content to maximize performance.
Divergence of Dynamometer Card Analysis from Actual Field Results at Light and Heavy Oil Fields of Mehsana
Authors: Chanchlani Kuldeep , Gogoi Ranjit , Awasthi Sukumar , Gunwant Deepak , Khanduja Nikhil 
Published: October 2022

Abstract
The performance of rod pumped wells are analyzed based on routine monitoring methods of echo meter and dynamometer analysis. There are 1080 sucker rod pumps installed in various fields of Mehsana. Rod pumps fail due to rod-tubing wear and aggressive fluid-reservoir conditions. Diagnostic studies are carried out promptly to predict the cause of rod pump failure. Circulation and crane troubleshooting jobs are taken post-diagnostic jobs to confirm the failure mechanism. This paper will discuss prominent mechanisms of rod pump failure, the use of dynamometer cards to track failure, and troubleshooting jobs to prevent failure.
In heavy oil fields, when the pump ceases to flow, the acquired dynamometer card showed a standing valve or traveling valve or both choked up. During troubleshooting by crane, polished rod load depicted sucker rod unscrewing or parting. The reasons for the divergence of dynamometer cards from troubleshooting jobs are the variation of fluid load due to fluid characteristics. The accessed dynamometer card indicates gas interference or gas lock despite low casing head pressure in light oil fields. During circulation job execution, the initial pumping pressure of the surface pump is quite high, which indicated obstruction across the subsurface pump. The obstruction causes no freefall of polished rod, requiring servicing by workover rig. During the pullout of the subsurface pump by workover rig, observations included downhole screen choked, gravel pack failure, wax deposition on sucker rods subsurface pump, and tailpipes choked with fine sand.
Solids incursion in light oil fields and rod unscrew in heavy oil fields are difficult to differentiate on basis of dynamometer cards. This paper will be fruitful to operators in identifying the cases, where the dynamometer card interpretation and analysis deviate from field practices.
Lessons Learned and Achievements from a Successful Sand Control Campaign in Ultra-Deepwater Gas Wells, East Africa
Authors: Martocchia Francesco , Deffieux Damien , Obanor Nelson , Battaglia Francesco , Palumbo Daniele , Rusconi Alessandro , Ricci Giovanni , Passini Lucio , Nhambi Gisela , Chirindja Joaquim , Chituto Hermenegildo 
Published: October 2022

AbstractSuccess in deploying sand control systems is critical to guarantee the integrity of wells during their productive life. This is even more crucial when dealing with ultra-deepwater high-rate gas wells.This paper will describe the challenges and the lessons learned from the successful 2021 completion campaign of X field in East Africa in which six gas producer wells were completed with openhole gravel pack using shunt tubes technology in water depths ranging from 1840 m to 2149 m.The overall completion design philosophy was to rely on field-proven technologies and industry-accepted "best practices" to maximize safety and reliability. This objective was pursued in all phases of the project for timely completion of the wells while minimizing the chance of failure.Extensive testing on formation rock cores and completion fluids was performed before the start of drilling to identify the best sand control strategy and to avoid all potential issues such as formation damage or fluid incompatibility.State-of-the-art completion equipment was selected considering all potential contingencies associated with operations in an ultra-deepwater environment in a remote location.This document will describe the activities carried on during the different phases of the project: design, preparation, execution, and post-job interpretation.The goal of preventing solid production without impairing the well productivity was achieved successfully. This was confirmed from well testing interpretation where neglectable skin was detected.At the same time, it was possible to carry on the completion activities on time and on cost despite the remote location and the challenges related to the ultra-deepwater environment.
Successful Implementation and Optimization of MLT Technology
Authors: Hilles Ahmed , Kassem Youssef Ali , Beaman Daniel , Wang Kechang , Butler Benjamin 
Published: October 2022

Abstract
This paper highlights the successful installation of a MultiLateral Technology (MLT) for the first time in an offshore field 40 km from Abu Dhabi. It will document the deployment of the deepest cemented MLT Level 5 globally, with improvements in well design and operations sequence compared to the conventional design and execution plan.
The system is demonstrated as a reliable method to access laterals giving the utmost importance to all operational risks concerning drilling and completion. The design relies on the Latch Coupling (LC) pre-installed with the production casing as the foundation for the successful drilling and cementing of the upper drain liner and for different completion runs. The downhole completion components that are permanently installed provide the capability for future reservoir monitoring and intervention to the laterals via coil tubing, wireline or slickline through the Multilateral Tieback System (MLTBS) completion.
The well was completed as the deepest cemented Level 5 System globally with zero NPT on MLT completion operations. The planning phase was extremely meticulous and all risks were properly identified at planning stage and mitigated during execution. The significant developments to multilateral construction are:
Optimize well profile, mud system, clean out and milling BHAs to facilitate the deployment of MTLB system. Improve the operations sequence by replacing the Retrievable Bridge Plug (RBP) run with intermediate completion. The assessed amendment has reduced four (4) trips during installation which has been recognized as a global system improvement for MLT Technology. Utilizing a glass device for the well barrier instead of slickline plugs have efficiently reduced the time and simplified the operation's intervention. Selecting to spot Hi-Vis after isolating the lateral instead of the sand has effectively improved the metal recovery and clean wellbore post clean up approach. The challenge of clean out post washover was moderated with fabricating a stinger to pass inside the packer and achieve proper debris cleaning to the seal bore area.
The well achieved its objective by providing two integral laterals with mechanical and hydraulic isolation and full accessibility of both drains for better reservoir surveillance through one single well slot. MLT installation strategy was effectively optimized to reduce time, cost and installation's risk against the original plan. The design enhancements were beneficial to achieve multiple global records.
Smart In-Situ Gas Lift System Using ICVs and Dial System
Authors: Saqib Talha , Mirza Omar Tajammal , Sabri Abdel Moez , Al-Hassan Sultan Dahi , Al-Hajri Saeed Salem , Mefleh Issam Rezk 
Published: October 2022

Abstract
The field that will be discussed here is a giant heterogeneous carbonate field which is located in the Arabian Gulf approximately 135 km north-west of Abu Dhabi. The field consist of multi-stacked heterogenous reservoirs. The reservoir T is the shallowest reservoir which is still undeveloped and measures 9 km by 11.5 km, with OOIP estimated in 2.3 BSTB. The reservoir is sub divided into 2 layers with the gravity 35 °API oil with initial gas oil ratio of about 350 scf/STB.
The reservoir pressure is 2,700 psi and the wells could not flow naturally due to low productivity and relatively low GOR against the high sealine pressure of more than 1,100 psi. There are only couple of solutions to produce these from this reservoir; either to lower the sealine or introduce "artificial lift".
The wellhead towers in the field are old and don't have luxury of either gas lift or ESPs. A detailed and comprehensive study was performed, and a collaborative team of engineers was assigned to find a sustainable and cost-effective solution to produce reservoir "T" in order to evaluate its potential. The team conducted a detailed and comprehensive study of the field starting from reservoir "T" and then expanded to the other reservoirs. As a result, the proposal of an "In-Situ Gas Lift" (Auto Gas Lift) pilot was formulated to use gas from the reservoir "C" (underlying reservoir T) to lighten and artificially lift the oil produced from reservoir T.
Auto Gas Lift (AGL) was selected due to the following advantages: Cost-effective artificial lift system.No surface modifications required on the wellhead towers.No additional pipeline to be laid.
The completion has been designed in a way that the gas bearing zone will be perforated and DIAL system which enhances the efficiency of gas lift through downhole data monitoring and digital operations will be installed. Dial system will allow to adjust the downhole choke any time accordingly with the minimum power and footprint requirement at surface. The controlled produced gas will allow reservoir T to flow by reducing the hydrostatic head of the fluid column in the well.
As the reservoir is subdivided into 2 layers so, the 2 drains will be drilled in each layer and their contribution will be controlled by inflow control valves (ICVs) which be equipped against each drain in upper completion. This will also allow us to flow the drains either one-by one or control commingled. But the ICVs manipulation could only be done with the portable unit with barge.
Till date the artificial lift has not been implemented in the field, however ESPs will be installed and followed by the gas lift. The data gathering with AGL will help us designing the full fledge gas lift system in the field.
Lithofacies Based Fluid Prediction Using Machine Learning
Authors: Li Yunsheng William , Ali Syed Sadaqat S. , Maskeen AbdulMohsin Abbas 
Published: October 2022

AbstractGas, oil and water zones are critical aspects for geoscientists to evaluate. In each well, a geoscientist must determine where such zones are located based on available well data, such as gamma ray, resistivity, density, neutron porosity, etc. This article addresses how to identify the most important gas, oil, and water zones based on these conventional log curvesusing machine learning (ML) technology which utilize different kinds of neural networks algorithms that is increasingly popular in well log analysis (Leila Aliouane, et al. 2013).Traditionally, geoscientists use a combination of different log curves to identify trends to locate gas, oil, and water zones. This methodology typically uses cut-offs and/or crossovers of different log curves and it is not always reliable. The most commonly used method are the crossover of bulk density and neutron porosity and the cutoffs of resistivity, which is really helpful but not very accurate.ML is categorized as supervised learning or unsupervised learningaccording to whether training sample labels are provided (Witten et al., 2005; Kotsiantis et al., 2007).This paper proposes a new methodology that uses MLtechnology to predict gas, oil, and water zones. It first builds an Unsupervised Machine Learning (UML) model to predict the initial lithofacies. It then builds another Supervised Machine Learning (SML) model using different conventional log curves and tested gas, oil, and water zones as inputs, including the initial predicted lithofacies from each well to train the model. The model is then applied to predict the gas, oil, and water zones for all wells, without the need for additional test information.This automated workflow can achieve a very good result easily and accurately because the machine learning technology can fully utilize the input information to find the relationshipbetween the input data and the training data. By applying the lithofacies restriction to limit the output only within the good reservoirs,a very good final result was successfully achieved.At the end of the workflow a 3D model was also created to predict the distribution of the fluid. The 3D model shows clearly the gas, oil and water distribution horizontally and vertically which will help with field development in the future.