bluuebunny/crossref_metadata_2025_split huggingface dataset:
Staged-Fracturing Completion Technology for the Ultra Deep-Hpht High Inclination Well in the Keshen Gas Field: a Case Study
Authors: Wang Kelin , Wang Yan , Liu Hongtao , He Xinxing , Liu Shuang , Shan Feng , Jiang TianHong , Bu Lulu , Ding Liangliang 
Published: May 2021

Abstract
Keshen No. 10 gas reservoir has a large amount of resources, but the geological structure is complex, and three sets of faults are developed in the upper formation. Four vertical wells had been drilled in the last ten years, and only one well was drilled successfully. To develop the gas field, a high inclination well KSX was designed to avoid the faults. The final well depth is 7060m, maximum inclination was 76.6°, reservoir pressure was 103MPa, reservoir temperature was 154 °C, effective reservoir thickness was 115.5m, and the production casing was 7 3/4 inch with 5 inch liner. The staged-fracturing was designed to achieve a high production rate, and it was a major challenge for completion design and operation.
To meet the requirement of staged fracturing, the different completion technology including bridge plug isolation, packer isolation and temporary plugging of perforated intervals were evaluated, and the combination of packer isolation and temporary plugging was finally chosen. Based on the casing program, 7 3/4 inch + 5 inch double packer combination was chosen preferably. Also, systematic analysis was conducted for the past failure case of double packer fracturing in the HPHT well, and it was clear that excessive axial force was the key factor of packer failure. Therefore, expansion joint was set between the packers to relieve the axial force on the packer during the fracturing. In addition, the soluble ball was chosen to open the sliding sleeve to conduct the next interval fracturing operation.
During the completion operation, wellbore treatment, packer centralization and the other auxiliary measures were taken, completion string was successfully run in the expected depth, and the packer setting was also normal. During the fracturing operation, the target intervals were divided into two zones by both soluble ball and packers, the fiber temporary plugging of perforated intervals were completed in each zone, and the temporary pressure was up to 7 MPa. The total injection fluid volume 2562m3, total sand volume 159m3, maximum flow rate 6.55 m3/min, maximum pump pressure 118.5MPa. After fracturing operation, the production rate 740,000 m3/d was obtained with wellhead flow pressure 75MPa, and the rate was 2.6 times larger than the vertical well.
Stems as Natural, Green, Non-Toxic Corrosion Inhibitors
Authors: Ng Jun Hong Clarence , Almubarak Tariq , Nasr-El-Din Hisham A. 
Published: May 2021

Abstract
Corrosion during acid treatments causes severe damage to the tubulars and downhole equipment. Consequently, this leads to an increase in expenditure to maintain well production rates and well integrity. NACE estimates the cost of corrosion costs to be roughly 1.372 billion USD annually to the industry, making corrosion control extremely important. Therefore, corrosion inhibitors must be included in any acid treatment formulation. This work aims to develop environmentally friendly and non-toxic corrosion inhibitors that can work in the harsh oilfield conditions. Samples of 10 different stems were tested as sources of potential corrosion inhibitors.
To determine the inhibition effectiveness of the different samples, N-80 coupons were exposed to 15 wt% HCl solutions at temperatures between 77-200 °F with 2 wt% of each sample for 6 hours. In addition, a control solution containing no corrosion inhibitor was used to establish a corrosion rate for a base case.
At a concentration of 2 wt%, sample 1, 2, and 3 were found to perform the best, exhibiting 94.4% to 99.9% corrosion inhibition efficiency at 77°F. Sample 8 was observed to perform the worst with a corrosion inhibition efficiency of 57.3%. At 150°F, the corrosion rate of sample 1 was found to be 0.0275 lb/ft2, while that of sample 2 was 0.0171 lb/ft2. At this temperature, sample 3 did not perform well, exhibiting a corrosion rate of 0.155 lb/ft2 and thus was not tested at higher temperatures. At 200°F, the addition of a corrosion inhibitor intensifier resulted in a corrosion rate of 0.0136 lb/ft2 for sample 1 and 0.00878 lb/ft2 for sample 2. These results show that a naturally occurring, green, non-toxic corrosion inhibitor can be developed from these stems and can comfortably pass the industry requirement for low carbon steel.
Currently used corrosion inhibitors are associated with environmental concerns and severe health risks. Recent developments in corrosion inhibition technology successfully tackled the environmental concerns, but still faces issues with toxicity and performance at high temperatures. The results in this work share two new naturally occurring, green, non-toxic, high-temperature stable corrosion inhibitors that can be developed from stems and can successfully protect the tubular during acid treatments.
Unlocking Oman's Tight Gas Potential using State-of-the-Art Underbalanced Coiled Tubing Drilling Technologies
Authors: Lynn Stephen , Manoharan Sumith , Barkat Souhaibe , Al-Ruzeiqi Saleh , Terras Yan , Kindi Ahmed , Khaldi Saud , Sibani Ahmed , Ajmi Hussain , Ruqaishi Abdullah 
Published: May 2021

Abstract
With the large amount of tight gas reserves remaining in Oman, new innovative techniques and methods to unlock these reserves have become imperative for the future economic success and stability of the country.
Among the various technologies considered, the concept of underbalanced coiled tubing drilling (UBCTD) was introduced. In order to address the harsh downhole challenges such as high temperatures, deep burial depths, under pressured reservoirs, abrasive and hard sands and logistical constraints; a fully integrated well delivery solution was developed jointly by the operator and energy service company.
In accordance with this strategy, best in class downhole drilling tools, a state-of-the-art fully automated coiled tubing drilling unit together with technical and project management experts were deployed. Application specific solutions to the challenging subsurface conditions included utilization of underbalanced drilling (UBD) techniques, deployment of high temperature drilling assemblies, fit-for-purpose bit drive mechanism and a robust integrated management system. All of the above was achieved whilst ensuring the safety of all personnel during the project and reducing carbon emissions through a flare minimization strategy and diesel consumption reduction initiatives.
Over the course of the pilot campaign, reservoir exposure per well was doubled, average penetration rate compared to conventional rotary drilling was more than tripled and incremental production improvements of up to 230% were observed. This paper discusses the challenges faced and the solutions implemented during this three well pilot campaign.
Drilling Efficiency Benchmarking Tool: Developing A Drilling Performance Measure Combining Data Science and Statistical Approach
Authors: Bimastianto Paulinus , AlSaadi Hamdan , Khambete Shreepad , Cotten Michael , Couzigou Erwan , Al-Marzouqi Adel , Chevallier Bertrand , Qadir Ahsan , Pausin Wiliem 
Published: May 2021

Abstract
Majority of organizations endeavor to reduce operating costs and improve operational efficiencies. The concept of Mechanical Specific Energy (MSE) has long been implemented in the industry to improve drilling performance. The Drilling Real time Operations Center (RTOC) has taken the concept of MSE beyond its traditional approach by developing a Drilling Performance Measure combining data science and statistics to benchmark drilling efficiency.
To extract maximum value from the available database, a workflow was developed to construct a Drilling Efficiency Benchmarking Tool. The different steps will be described for performing the data ingestion, cleansing, selection (offset well selection), methodology of computing the statistical model for MSE baseline per Formations and visualization of the output (charts and logs), to compare the actual MSE with baseline and thereby measuring the performance efficiency.
The offset wells analysis results show that the workflow can construct an MSE baseline using high frequency data in a meaningful way, which is then set as a target envelope and projected through the real-time platform for monitoring and intervention purposes. This implementation of real-time MSE benchmarking helps identify the area of potential improvement, optimize drilling parameters to ultimately improve ROP and minimize lost time. As an analytical tool, it highlights achievable performance for each field and provide insights to consider new Best Practices.
Benefits of Using Continuous Circulation Systems in ERD Wells to Manage ECD, Bottom Hole Pressure and Hole Cleaning
Authors: Petrie Scott William , Doll Rick 
Published: May 2021

Abstract
Continuous Circulation Systems (CCS) have been around since the JIP between Shell, BP, Statoil, BG, Total and Eni in October 2000. Initial reports of these systems demonstrated that while cumbersome, the use of CCS is of benefit to drilling ERD wells. Continuous circulation keeps cuttings moving out of the wellbore, reducing or eliminating the time required to circulate clean any high-angle section before making a drill pipe connection or before tripping out of the hole.
Continuous Circulation over each connection enhances the management of Equivalent Circulating Density(ECD) to control the bottom hole pressure on the well by never switching off the pumps, therefore the wellbore never experiences an Equivalent Static Density(ESD). Through this mechanism, the application of CCS has also been proven to manage bottom hole pressure constantly, which in conjunction with good drilling practices for torque and drag management, are key factors in drilling any Extended Reach Drilling(ERD), Complex or High Pressure/High Temperature (HPHT) well.
High Performance Drilling Onshore Abu Dhabi
Authors: Kuyken Chris Wilhelm , Elkasrawy Mohamed Elsaied , Al Breiki Ali Mubarak Saeed , Elgendy Yahia Abdelfattah Mahmoud , Abdelaal Ahmed Gamal 
Published: May 2021

Abstract
High performance drilling is an approach applied in the drilling of hole sections that are not primarily benefitting from data acquisition except the minimum like gamma ray and directional. Therefore these sections are drilled with high ROP and subsequently cased in support of reducing well costs.
High performance drilling leading to continuous ROP optimization has been proven a key enabler for invisible lost time reduction (ILT), being one of the current regional well delivery challenges. In this paper we explain the approach followed by the team comprising of operator, service provider and equipment provider in reducing the impact of ILT during the actual drilling phase. We learnt that creating a performance culture based on rigorously applying of best practices and the eagerness to continuously improve on past performance as a first strategy and the application of novel directional drilling motor technology as the second resulted in ROP performance records. For example in one field an average ROP record was achieved of 188 ft / hour a 15 % improvement from the previous record.
We learnt that in particular the communication between all parties i.e. the client office, the service provider and the team on the rig was the most important factor in order to create a shared vision on the need to improve the ROP based on the last ROP performance benchmark.
Secondly the latest motor technology and the way of how it gets deployed, available to the team played a major role, and brought the performance level to a new dimension whereby the ROP was targeted to be optimum instead of maximum thereby reducing the risk for NPT related incidents (hole problems, equipment break-down) and repair and maintenance cost becoming cost prohibitive.
This paper is specifically meant to share best practices from the last 10 years with the larger UAE drilling community. It is service provider contribution to provide insights for the new generation drilling engineers and directional drillers in safely pushing the drilling performance to higher levels all the time targeting the ILT in hole making.
The work has proved that a combination of low torque high speed and high torque low speed can successfully performance drill all vertical hole sizes in the UAE on-shore fields either using tri-cone or PDC bits.Figure 1High performance motor
Early Anomaly Detection Model Using Random Forest while Drilling Horizontal Wells with a Real Case Study
Authors: AlSaihati Ahmed , Elkatatny Salaheldin , Mahmoud Ahmed , Abdulraheem Abdulazeez 
Published: May 2021

Abstract
There has been discrepancy between the pre-calculated and actual T&D values, because of the dependence of the model’s predictability on assumed inputs. Therefore, to have a reliable model, the users must adjust the model inputs; mainly friction coefficient in order to match the actual T&D. This, however, can mask downhole conditions such as cutting beds, tight holes and sticking tendencies.
This paper aims to introduce a machine learning model to predict the continuous profile of the surface drilling torque to detect the operational issues in advance. Actual data of Well-1, starting from the time of drilling a 5-7/8-inch horizontal section until one day prior to the stuck pipe event, was used to train and test a random forest (RF) model with an 80/20 split ratio, to predict the surface drilling torque. The input variables for the model are the drilling surface parameters, namely: flow rate, hook load, rate of penetration, rotary speed, standpipe pressure, and weight-on-bit.
The developed model was used to predict the surface drilling torque, which represents the normal trend for the last day leading up to the stuck pipe incident in Well-1. Then the model was integrated with a multivariate metric distance, Mahalanobis, to be used as a classifier to measure how close an actual observation is from the predictive normal trend. Based on a pre-determined threshold, each actual observation was labeled as "NORMAL" or "ANOMAL".
Deviated Drilling Through Salt Dome and Horizontalization Across Extremely Heterogeneous Formations: A Case Study in North Abu Dhabi
Authors: Nunez Ygnacio Jesus , Sameer Mohamed , Ruiz Fernando , Al Mutawa Ahmed Abdulla , Al Shamisi Eisa Daban , Hamdy Ibrahim , Al Hendi Mohamed , Al Dhaheri Khaled Hamad , Torres Javier 
Published: May 2021

Abstract
Over the last 60 years, Abu Dhabi, United Arab Emirates (UAE) has been producing oil and gas from different conventional fields. Nowadays, and as part of the State long-term strategy to achieve the nation objective of gas self-sufficiency, it has been decided to explore, appraise and develop unconventional plays in the Northern area including the construction of early production facilities to supply the gas power plants. Three wells were drilled as part of the first phase of the project; consisting of a pilot hole into an extremely heterogeneous formation; two of them were horizontalized into the targeted formations. The first well across the salt represented a tremendous challenge due to limited rig capacity generating hole stability issues that required unplanned remedial jobs. The second well was deviated across the salt as pilot hole, then side-tracked and horizontalized in the targeted reservoirs. The third well was drilled directly as horizontal lateral based on previous lessons learned validating the horizontal concept for the future field development plan.
The exploration phase constituted by these three wells, were drilled and completed successfully. A detailed data gathering program was executed allowing mapping of the area validating the presence of gas. The drilling parameters, such as rate of penetration (ROP) for the horizontal section was enhanced by optimizing the drilling Bit design. The mud logging results have confirmed the extremely heterogeneous formations across this section allowing determining the most fit for purpose bottom hole assembly (BHA); obtained after a detailed optimization process. Multiple lessons learned were captured and immediately applied leading to a significant reduction on total days per well that reflected on an outstanding cost reduction including rig move optimization, incrementing the overall efficiency of the operations. This project has proven the potential of unlocking the development of this field focusing on the targeted untapped reservoirs. Key unprecedented achievements have been fulfilled during the execution of this phase of the project: 1. First time to drill across a salt dome in Abu Dhabi Emirate 2. First time that horizontalization has been applied to the targeted formations. In addition, a better understanding of the optimum drilling parameters for future phases has been obtained.
A Challenging Drilling Campaign Unleashed a Unique Fast Drill String Recovery Methodology Eliminating Utilizing Wireline, CT and Overcome Highly Deviated String Accessibility
Authors: Abdelhalim Khaled , Al Zaabi Mohamed , Al Ali Salim , Abdel Karim Islam khaled , Jadallah Haitham , Al Beshr Abdul Rahman , Endo Shigeru 
Published: May 2021

Abstract
Stuck pipe is one of the biggest challenges in the drilling sector and is a multi-billion-dollar issue. Recovering from stuck pipe absorbs significant cost and time. Durations for stuck pipe events and recovery can be mostly variable from a few days to up to over a month to resolve.
When attempts to release the stuck pipe by jarring or acid fail, the operating company and drilling contractors are left with little option but to sever the drill string and prepare for side-track operations or even abandon the hole. Traditional pipe severance methods in the event of a stuck pipe situation typically take significant time (often days, and sometimes weeks), require specialist tools, Service Hands, and are usually reliant on wireline services to deliver the severance method.
In 2018, a Major Operating Company in UAE faced a challenging high-sticking Formation, which caused massive NPT, stuck of drill strings, and loss of drilled section holes.
Brainstorming within the Drilling Engineering team took the campaign to the next level of pre-planning to reach deep access in the hole to be able to achieve zonal isolation by spotting cement plugs through drilling BHA, find a solution to save the hole and recover the pipes in an efficient, cheap and productive manner.
An environmentally safe pre-planned solution to severe the drill string was proposed to help save the wells and allow an excellent methodology to save the wells/fields from stuck pipe risks.
The engineering solution allows a fast recovery of drill pipes using a downhole tool as a part of drilling BHA, with the option to activate it if required, by dropping a smart dart and circulating with mud for a specific time to apply cut string with two option, either spotting cement with recovered BHA or lift BHA with fish neck to try to fish in the hole.
Best Practices Implementation during 7" Liner Milling Operation
Authors: Iftikhar Choudhry Bilal , Khaled AbdelKarim Islam , Alfonso Mendez Freddy , Ahmed Osman Mohamed , Hassan Youssef Karim , Samir Ismail Ahmed 
Published: May 2021

ABSTRACT
The paper explores the 7" liner milling operations in re - entry well bores, operations that have become fairly common especially at the interface of corrosive effluents or after an extended life time. This however being a time and efficiency driven choice highlights the need for optimization from both the performance as well as the operational time perspective. The flat time endemic to the milling operation execution however, can be reduced and the operations can be optimized with effective mills, fine tuned rheological parameters of the milling fluid, the BHA stabilization and the finger printing of the milling parameters put in place to execute the entire operation. This paper looks into the various facets of optimization that can expand the avenue of flat time reduction and milling operations execution.
Considering the various wells in the database considererd vis – a – vis the milling operations, a baseline ROP of 2 – 6 FPH for liner milling can be established. The baseline reference for this operation averages out an approximate of a couple of weeks from the well duration and has inherent complications both of which can be circumvented with optimization. Albeit the best proponent for mill selection is the existing liner configuration downhole, however this is one luxury that is not available in most cases. More often than not, the maiden mill run is done in a well with the least amount of data available regarding the existing well casing state. Therefore, adequate mill selection and mill cutting structure preparation hold significane for the successful execution, after all each milling run dictates the progress of the successive one. The paper also looks into the proponents of operational optimization and the denominators that drive the successful execution of the job.
Record Length Chrome Liner Run Using Innovative, Low-Marking, Non-Ferrous Dies on a Mechanical Casing Running Tool
Authors: Guzman Marco Cespedes , Ozirny Scott Jason , Smith Douglas Grant 
Published: May 2021

Abstract
Abu Dhabi National Oil Company (ADNOC) has steadily advanced toward the use of a casing running tool (CRT) vs. conventional casing running methods to improve efficiency and safety. This advancement focused mainly on 9 ⅝ in to 20 in diameter casing and utilized internal grip tools. Recently they have searched for an external-grip CRT system that would allow them to effectively run the smaller diameter liners of both ferrous and chrome (Cr) materials, especially in the extended reach drilling (ERD) wells with maximum reservoir contact (MRC).
For 20 years CRT companies manufactured tools with gripping dies that could efficiently run ferrous material liners. Development of gripping mechanisms which can effectively run corrosion resistant alloy (CRA) materials has been met with varying success. Some of the challenges are to manufacture gripping dies from non-ferrous materials that will not contaminate the CRA liner and develop a gripping pattern that does not mark the CRA liner more than is accepted by API 5CRA industry standards, but maintain effective gripping force. In addition to hoisting and making up the string with no slippage it needs to perform fluid circulation at 3,000 psi. Until recently the liners were typically run in a conventional method using power-tongs.
One of the tools chosen for the trial runs was a well-proven, external-grip mechanical CRT designed specifically for smaller diameter casing and liners. It has a 500-ton hoist capacity and a 5,000 psi circulation rating and was packaged with a combination float and cushion tool and a wireless torque turn sub. Dies had been designed to meet the non-contamination and acceptable marking criteria previously mentioned and would be compatible with liners possessing as much as 25% Cr. The dies had been extensively lab-tested, including heavy pull tests and torque application tests, but had not previously been used in field applications.
The ERD-MRC well chosen for this trial was planned to have a record length of 6 ⅝ in, 24 ppf, 13% Cr liner with a wedge thread premium connection. In addition to not contaminating the liner, ADNOC expected an average running speed in joints per hour equivalent to the conventional casing running methods and a reduction in time during circulations.
The result of the trial was 589 connections (25,035 ft liner length) successfully run with an average running speed matching their expectations. The liner displayed very minimal marks and there were no issues when hoisting or torqueing the connections. In addition, there were no rejected connections during the run.
This publication will review the preparation for the run, actual run details, photos of the die marks, torque graphs and conclusions expressed by the operator with recommendations for changes moving forward.