bluuebunny/crossref_metadata_2025_split huggingface dataset:
Role of Geomechanics in Identification of Possible Mechanisms for Non-productive Times NPT and Improving Drilling Operations in a Mature Field in Offshore Sarawak, Malaysia
Authors: Chatterjee Avirup , Ghosh Amitava , Santha Moorthy Priveen Raj 
Published: October 2021

Abstract
This paper presents a case study on the role of geomechanics to identify possible failure mechanisms for non-productive time (NPT), avoid drilling risks and minimize costs in a field development drilling campaign, Offshore Sarawak Malaysia. Drilling optimization and reducing NPT for the drilling campaign was one of the key focus for maintaining the drilling time and costs. Drilling of moderately to highly deviated wells in this field has proven to be extremely challenging. Numerous lost-time incidents due to tight hole, stuck pipe, pack-off, casing held up were experienced, particularly when drilling through the shallow overburden shales and deeper reservoirs interbedded with shales and coals. Faced with continually increased NPTs, a geomechanical model was developed using regional offset wells to understand the mechanism of failures. A geomechanical model was developed to quantify the minimum recommended mud weights and optimize the wellbore trajectories. The outcome of this study was used as key input for casing and mud design. The in-situ stress state derived from field wide geomechanical model indicates the field is associated with a normal faulting stress regime, i.e., Shmin &lt; SHmax &lt; SV.
The presence of relatively weak rocks means the field is potentially subject to stress-induced wellbore instability problems. However, observations of numerous time-dependent failures imply secondary influences must also be considered to arrive at possible remediation strategies. It was observed that the combination of weak rocks and numerous time-dependent failures using different types of mud system have contributed to wellbore stability problems. The wellbore stability is due to reactive shale, which is time sensitive as majority of the drilling problems are observed after drilling. The major contributor to the time-dependent deterioration process is mechanical and chemical imbalances between shale and drilling fluids compounded by large open-hole exposure area and contact time resulting in rising pore pressure caused by the invasion of drilling fluid into the formations, and then exacerbated by less-than-optimal drilling practices. This finding, together with improved geomechanical understanding of the field helped to evaluate the safe mud weight windows, formulate the mud designs and optimize drilling practices. All the planned wells were drilled successfully without any loss time incidents and non-productive time. This paper presents an integrated approach and workflow that combines the drilling data and formation response to identify the most likely causative mechanisms of the time-delayed wellbore instabilities in a mature field. This knowledge was then used to develop strategies for optimizing future drilling operations in the field.
Digital Solutions Suite: Big Data, Artificial Intelligence, and Digital Barrel
Authors: Fuenmayor Roberto Carlos 
Published: October 2021

Abstract
The concept of digital transformation is based on two principles: data driven—exploiting every bit of data source—and user focused. The objective is not only to consolidate data from multiple systems, but to apply an analytics approach to extract insights that are the product of the aggregation of multiple sources then present it to the user (field manager, production and surveillance engineer, region manager, and country) with criteria's of simplicity, specificity, novelty—and most importantly, clarity.
The idea is to liberate the data across the whole upstream community and intended for production operations people by providing a one-stop production digital platform that taps into unstructured data and is transformed into structured to be used as input to engineering models and as a result provide data analytics and generate insights.
There is three main key objectives:
To have only one source of truth using cloud-based technology To incorporate artificial intelligence models to fill the data gaps of production and operations parameters such as pressure and temperature To incorporate multiple solutions for the upstream community that helps during the slow, medium, and fast loops of upstream operations.
The new "way of working" helps multiple disciplines such as subsurface team, facilities, and operations, HSSE and business planning, combining business process management and technical workflows to generates insights and create value that impact the profit and losses (P&L) sheet of the operators.
The "new ways of working" tackle values pillars such as production optimization, reduced unplanned deferment, cost avoidance, and improved process cycle efficiency. The use of big data and artificial intelligence algorithms are key to understand the production of the wells and fields, as well as anchoring on processing the data with automated engineering models, thus enabling better decision making including the span of time scale such as fast, medium, or slow loop actions.
Vapour-Liquid Equilibrium Study for the Carbon Dioxide and Hydrogen Sulphide in Deionized Water and NaCl Aqueous Solution at Temperature from 373.15 to 423.15 K
Authors: Zaidin Mohd Fakrumie , Valtz Alain , Coquelet Christophe , Chapoy Antonin 
Published: October 2021

Abstract
New vapour liquid equilibrium (VLE) data for carbon dioxide (CO2) and hydrogen sulphide (H2S) mixture in deionized water and NaCl aqueous solution are generated at temperature range from 373.15 to 423.15 K and pressure up to 25.0 MPa. A static-analytic type method, taking advantage of two magnetic capillary samplers for phase sampling is used for this VLE measurements. The VLE data generated in this work are compared against literature data, Duan model and the simplified cubic plus association (CPA-SRK72) Equation of State (EoS) model predictions. From the results, it is demonstrated that the CPA-SRK72 EoS model is able to predict the phase behaviour of CO2 and H2S in water and NaCl aqueous solutions with low absolute average deviation (AAD) against the measured experimental data.
Enhancing Reservoir Stimulation and Productivity Through Reservoir Tunneling Technologies: A Review on Recent Development
Authors: Alali Eyad A. , Bataweel Mohammed A. 
Published: October 2021

Abstract
The oil and gas industry has been developing various technologies to increase the productivity and recovery of hydrocarbons from conventional and unconventional reservoirs. Reservoir stimulation is an essential operation used to enhance production in many fields around the world. Hydraulic fracturing and acid treatments are the main stimulation methods. Reservoir tunneling concepts are used to drill branched channels in the formation from the main wellbore. With thousands of tunnels drilled to date, it is a viable technique that can improve the recovery of selected reservoirs.
This paper reviews the recent developments in reservoir tunneling technologies and their current applications. These tunneling methods can be categorized mainly into water jetting, abrasive jetting, reactive jetting (acid), and needle and mechanical tunneling (radial drilling). The paper includes reviewing and analyzing these techniques based on documented literature results that include simulation studies, lab and yard experiments, field implementation, candidate selection, operational requirements, technology enhancements, advantages, limitations, and challenges of each technique.
The paper provides a comprehensive summary of different tunneling techniques focusing on the operational practices, tunneling mechanisms, tunneling depth, and recent advancements available in the market. The most effective applications of the tunneling techniques are in stimulating low permeability, depleted and thin reservoirs, layers close to water zones, and bypassing near wellbore formation damage. The efficiency of creating tunnels is affected by many factors such as reservoir properties, nozzle, and fluid types, etc. The tunnel shape and trajectory are affected by reservoir geological properties. The combination of the tunneling with other stimulation techniques can result in more effective treatments, which enhance the methods of current stimulation. Reservoir tunneling technologies can pave the way to improve hydrocarbon recovery and enable access to unstimulated formations.
SNB AOI Topside Design Optimization: Solution for Marginal Resources
Authors: Mubarok Rudi Syahru , Andriana Monica , Prabowo Albertino 
Published: October 2021

Abstract
Sisi Nubi Area of Interest (SNB AOI) is an ongoing project to develop the marginal resources located in Sisi Nubi offshore field operated by Pertamina Hulu Mahakam (PHM). As the resources being developed are small and scattered, low cost solution platform design is required to develop these marginal resources. Therefore, design optimization is a must.
Fit-for-purpose design concept is used as the basis to develop process and safety facilities in new SNB AOI platforms while maintaining the compliance with government regulations and international codes and standards. Various exercises were performed in order to ensure optimized process, safety and operating philosophy requirement. Lesson learnt and benchmarking from various established platforms design including PHM's minimalist offshore/swamp platform were performed. The previous designs are reviewed, adopted and SNB AOI platform design is adjusted as per operating philosophy requirement.
Based on the available basis of design and operating parameters, fully rated topside facilities design is considered feasible to be applied for new SNB AOI platforms. With this design, relief system size (i.e. vent stack and vent knock-out drum) can be further optimized. In addition, closed drain drum and LP (low pressure) vent knock-out drum is also combined in one single vessel after careful safety verification. Other optimization is externalizing equipment that could be managed with Operating Expenditure (e.g. well offloading activity by using external facility).
As for process safety design, preliminary reviews based on international codes and standards showed that the following designs are considered feasible: portable Gas Detector by operator during platform visit (in lieu of permanent Gas Detection system), Fusible Plug loop installation only (instead of redundant protection using Flame Detector system), non-provision of dry fire water mains, application of Passive Fire Protection (PFP) only after confirmation from fire risk study (risk-based approach), and considering not permanently manned installation, 1 (one) stair & 1 (one) ladder combination on each platform deck (instead of dual stairs). Overall, the proposed design maintains the safety of installation with minimum impacts to future platform operation.
This optimization has contributed to reduction of dimension and weight of topside installation (i.e. 32% less compared to PHM's latest Offshore Minimalist Platform design) and also weight of the structure.
Design of SNB AOI project could become a good reference for other Pertamina affiliate and other companies and could open a further way forward to economically develop the "marginal resources", especially in offshore area, by implementing the "fit for purpose" design concept.
Unconventional Single Slurry Solution for ERD Wells with Depleted Formations
Authors: Flores Anibal , Vasquez Jorge , Anggarawinata Rama , Chan Lakmun 
Published: October 2021

Abstract
Tailoring slurry designs using amorphous liquid silica base has been a success for Cementing Extended Reach Drilling (ERD) wells in Brunei in development fields. The use of this unconventional slurry density and design has helped to achieve the necessary top of cement and required zonal isolation for the production string of these wells.
Cementing across depleted formations has been a challenge for the drilling sector within the oil industry. Isolation of production zones with competent cement slurries has become a necessity in fields, especially where a low Equivalent Circulating Density(ECD) during the cementing operation is required to achieve the desired top of cement in low fracture gradient formations. For Brunei offshore operations a novel approach has been proposed that uses an amorphous liquid silica-based slurry system to design a new 14 ppg lightweight cement slurry. The slurry properties were tailored to eliminate the need for a dual slurry system. Planning, execution, and post-operation evaluation methods have been developed for this new design.
Extensive laboratory testing has been performed for the 14 ppg extended slurry which includes basic slurry testing as well as more advanced evaluations such as a full mechanical properties study and finite element analysis that was used compared to conventional slurry designs. Various optimizations were done for the slurry design to overcome mixability challenges and deployment using a conventional offshore liquid injection system or by premixing the water with liquid additives on a mixing tank or rig pits.
To validate this technology, a field trial was performed at the rig site where a production liner for an extended reach well was cemented and subsequently evaluated using cement evaluation logging tools.
The first Brunei offshore trial operation, executed in Q2 2020, was a 4.5-in. production liner where 16.5 m3 of a 14ppg novel slurry design was mixed, pumped and successfully placed within the annulus. Since the initial trial, a total of 8 jobs have been executed successfully in Brunei, with a few more wells identified as candidates for this solution. The paper provides laboratory testing details, hydraulic simulation validations along with job execution and post-operation cement evaluation.
A Success Story in Managing and Optimising Gas Lift Wells in Matured Oil Field: Automated Workflows in Digital Fields as Enablers to Accelerate Opportunities Creation and Production Optimisation
Authors: M. Nazri Amir Badzly , W. Khairul Anuar W. M. Anas , Avianto Nasution Lucas Ignatius , Turiman Hayati , Shafie Shar Kawi Hazim , Mokhlis Mohamad Mustaqim 
Published: October 2021

Abstract
Field S located in offshore Malaysia had been producing for more than 30 years with nearly 90% of current active strings dependent on gas lift assistance. Subsurface challenges encountered in this matured field such as management of increasing water-cut, sand production, and depleting reservoir pressure are one of key factors that drive the asset team to continuously monitor the performance of gaslifted wells to ensure better control of production thereby meeting target deliverability of the field.
Hence, Gas Lift Optimization (GLOP) campaign was embarked in Field S to accelerate short term production with integration of Gas Lift Management Modules in Integrated Operations (IO). A workflow was created to navigate asset team in this campaign from performing gaslift health check, diagnostic and troubleshooting to data and model validation until execution prior to identification of GLOP candidates with facilitation from digital workflows.
Digital Fields and Integrated Operations (IO) developed in Field S provided an efficient collaborative working environment to monitor field performance real time and optimize production continuously. Digital Fields comprises of multiple engineering workflows developed and operationalized to act as enablers for the asset team to quickly identify the low-hanging fruit opportunities.
This paper will focus on entire cycle process of digital workflows with engineer's intervention in data hygiene and model validation, the challenges to implement GLOP, and results from the campaign in Field S.
Remote-Controlled Automated Foam Injection: A Digital Solution to Liquid Loading in a China Unconventional Gas Development
Authors: Bo Jiang Wei , Audrey Beryl , Orivri Uzezi , Wang Nian Xi , Qiao Xiang Yang , Fendt Andrew , Kartoatmodjo Gayatri , Li Lin Wei , Song Yu Long , Qi Shi Wei 
Published: October 2021

Abstract
Gas field C is an unconventional tight gas reservoir located in the central of China which has prominent characteristics, including thin formation, low permeability and poor reservoir connectivity which significantly impact on the field development. Horizontal wells multistage hydraulic fracturing has been proven to be an effective technique to recover the hydrocarbons from this gas field.
However, with continuous production overtime, reservoir pressure declines which results in a decrease in gas production rate below the critical gas velocity, leading to accumulation of liquid in the wellbore (liquid loading), which further results in back pressure and damage to the formation. Currently, gas field C loses up to 1500 mmscf/year in gas production and associated revenue due to liquid loading. Some other factors which hinders effective deliquification of the gas wells include remote well pad locations, poor road conditions during harsh weather conditions, friction with local communities, limited manpower to daily effectively analyze over 200 wells for liquid loading diagnostics and operational risks during well intervention.
To tackle these challenges, a new versatile intelligent dosing technology has been piloted to reduce liquid loading. This remote-control dosing unit is located at the well pad and is equipped with automatic valves that can dispense two different chemicals (soap and methanol) in one unit. A key new feature of this system is the ability to receive and implement instructions that optimizes the dosing rate and frequency. This remote-control functionality eliminates on-site operator intervention and HSE risks especially in winter when the well pads could be inaccessible with poor road conditions.
Statistical Models to Predict Tensile Strength from Unconfined Compressive Strength: Case Study from Southern Iraq
Authors: Alkinani Husam Hasan , Al-Hameedi Abo Taleb Tuama , Dunn-Norman Shari , Al-Alwani Mustafa Adil 
Published: October 2021

Abstract
Tensile strength (To) is an important parameter for creating geomechanical models, especially when tensile failure is the failure of interest. The most common way to estimate the tensile strength is by utilizing Brazilian tests. However, due to material limitation, cost, or time, To is sometimes assumed or estimated empirically. In this work, laboratory test data of To and Unconfined Compressive Strength (UCS) conducted for three zones in southern Iraq (Zubair sandstone, Zubair shale, and Nahr Umr shale) were utilized to create three regression models to estimate To from UCS. The reason for selecting UCS as the independent parameter is that static UCS, in most cases, has to be estimated from laboratory tests to create robust geomechanical models. In other words, UCS will be given the preference over Towhen there is the material limitation, cost, or time involved. The data of each zone were divided into training (80%) and testing (20%) to ensure the models can generalize for new data and avoid overfitting. Multiple least squares fits were tested, and linear least squares regression was selected since it provided the highest R2 and the lowest error. The models yielded training R2 of 0.983, 0.988, and 0.965 while the testing R2 were 0.978, 0.990, and 0.993 for Zubair sandstone, Zubair shale, and Nahr Umr shale, respectively. The errors were assessed using root mean squared error (RMSE) and mean absolute error (MAE), and they both have shown an acceptable margin of error for all three models. In short, the created three models showed the ability to estimate To from UCS when material limitation, cost, or time factors are involved or when executing a Brazilian test is not applicable. The proposed models can contribute to robust geomechanical models as well as minimizing cost, time, and material usage.
Long Horizontal Well Completion via a New Flotation Technique
Authors: Shan Youngbin , Lu Hongjun , Jiang Qingbo , Li Zhijun , Xue Jianpeng , Tian Fengjun , Wang Yungong , Li Luke , Shi Chongdong , Shi Peiming , Yuan Bin , He Hangyu 
Published: October 2021

Abstract
The objective of the paper is to introduce a new technology which secures long horizontal casing deployment by a reliable casing flotation technology.
It is common nowadays to drill a slim hole and extends to long horizontal extension to pay zones in condensate and shale oil and gas reservoir.
To assure a successful casing deployment into the horizontal section, a flotation collar is often installed to float the casing in horizontal to mitigate the friction and Torque & Drag. However, slim casing may encounter difficulty in circulation and subsequent cementing even after the collar is broken.
A new proprietary technique proposed in this paper solved above contingencies and secured 100% success in casing deployment, This technique secures smoothly circulation and cementing by flotating air in horizontal casing interval and purging air out of hole to overcome Spring Effect before circulation and cementing.
Often, the flotation collar is made of proprietary material that can break or explodes under certain hydraulic pressure. After breaking, the whole collar becomes a portion of casing with exact the same ID of casing or a very small difference that does not have any negative effect to subsequent Plug & Perf, frac, tools running through and fluid movement.
For long horizontal length of small open hole and casing sizes, casing deployment may be difficult if the Torque & Drag and friction through the low sides can not be mitigated.
This paper proposes a new technique to fill air full of horizontal interval along inside the casing and ensure a sufficient of air purging to overcome Spring Effect before circulation and cementing.
So far twelve (12) wells have been successfully completed including Asian longest horizontal gas well with 7,388.18m measured depth and 4,118.18m horizontal length. All jobs are 100% successful and there is no difficulty in mud circulation and cementing. Even for the longest 4,118.18m horizontal length casing deployment, the hook weight on surface when casing reached the total depth still remained 20 MT.
Before this technique was applied, operators were unable to deploy 4 ½" casing through a 6" bit hole beyond 1500m horizontal length. Most often the hook weight at surface were zero when casing extended to almost 1500m in horizontal length.
This new technique brings a great value to operators to complete longer horizontal well to yield more production with less investment.