bluuebunny/crossref_metadata_2025_split huggingface dataset:
Achieving Repeatability and Reproducibility in Competency-Based Training
Authors: Lau Hon Chung , Pang Michael 
Published: October 2018

Abstract
In today's high-stakes E&P operating environment, achieving operational excellence is key not only to profitability but also obtaining a license to operate. Doing so requires E&P companies to have competent staff who are qualified to perform their jobs professionally at all levels of seniority. As technology and the regulatory environment change, continuous education for technical professionals is not only desirable but necessary. Competency-based training (CBT) is one of the most effective ways to ensure competency development in E&P professionals. Unlike traditional training, CBT focuses on helping the learner to master well-defined job-related competencies. The hallmarks of CBT are repeatability and reproducibility of results. Repeatability is the ability of the same learner to achieve consistent results whereas reproducibility is the ability of multiple learners to achieve the same consistent results. This paper discusses the ten elements of CBT in order to achieve repeatability and reproducibility.
Casing Drilling Technology as the Solution for Severe Lost Circulation: LSE Casing Drilling Pilot Project Case Study
Authors: Abdila Sayid Faisal , Harahap Andy Mahyuni , Yuristyanto Haryo , Muslim Aziz , Noviasta Bonar , Falhum Hanafi Muhamad , Astasari Kanya 
Published: October 2018

Abstract
The Louise (LSE) is one of the primary oil-producing fields in the Pertamina EP Asset V. This area has an issue with high potential of total losses in the top section [~400 m measured depth (MD)], which causes an inability to set the 13.375-in. casing at the required depth. As a result, this problematic zone must be drilled conventionally in two different sections, 17.5 in. and 12 .25 in., whilst combating losses. Pertamina EP spent up to 10 days as nonproductive time (NPT) to combat losses, resulting in high investment cost. A new innovative method was required to face this challenge with the objective of drilling deeper through the loss zone in a single run in a more effective and efficient and a safer way.
Nondirectional casing drilling technology was introduced to solve this problem. The casing drilling system simultaneously drills and runs the casing through the lost circulation zone in a single run, which provides a more efficient and a safer operation. Its plastering effect helps strengthen the wellbore by smearing cuttings into the wellbore wall, sealing pores in the formation to reduce fluid loss. At the same time, it saves the rig operating days by eliminating the loss-combating days and the dedicated casing run. The key driver of this technology is the drillable alloy casing bit specially made for drilling vertical or tangential wells, which can be drilled out by any standard PDC or milled tooth after it has drilled to total depth (TD) and the casing has been cemented in place.
On the pilot casing drilling project well, this system successfully drilled 351.25 m of 13.375-in. × 17.5-in. section to the casing point in a single run passing through the problematic loss zone. The 13.375-in. casing was cemented in place, and the casing bit was successfully drilled out using a conventional 12.25-in. PDC bit. Compared to the conventionally drilled offset wells, this technology enabled up to 220 m deeper 13.375-in. casing setting depth, which consequently eliminated the necessity of loss-combating activity in the 12.25-in. hole section.
The implementation of the casing drilling system solved the lost circulation problem and provided an additional benefit of eliminating a dedicated casing run. The casing drilling technology helped Pertamina EP to reduce the well drilling time by up to 4.75 operating days, saved up to USD 555,913 of drilling cost, and achieved 50 m deeper well TD compared to the plan. The pre-execution engineering work was one of the key activities leading to the success.
Development of Modified Rhizophora spp. Tannin Biopolymer Additive in Drilling Fluid System for High Temperature Well Applications
Authors: Ghazali Nurul Aimi , Naganawa Shigemi , Masuda Yoshihiro 
Published: October 2018

Abstract
The main objective of the current work is to investigate the performance of Rhizophora spp. tannin-lignosulfonate (RTLS) as a deflocculant in water-based drilling fluid (WBDF). Rhizophora spp. tannin (RT) was extracted from the barks, waste of conventional charcoal production. RTLS was synthesized and characterized by using Fourie transform infrared spectrometer (FT-IR) over a wide range of wavelength from 400 to 4000 cm−1 to determine the main functional group, and using thermogravimetric analysis (TGA) with the temperature range from 25 to 600°C to evaluate the thermal properties. Rheological properties of WBDF with the addition of RTLS as deflocculant were analyzed at room temperature condition and compared with industrial chrome-based deflocculant. The TG analysis revealed that RTLS has good thermal stability because the degradation temperature was observed at approxmately 280°C. The rheological properties demonstrated the yield point and the gel strength were reduced by addition of RTLS that indicated an improvement of the rheological performance. However, the trends for plastic viscosity showed a fluctuation with increasing in RTLS concentration because of the addition of suspended solid component in WBDF.
Overcoming the Challenges During Cementing Spacer Design for Deep Deviated HPHT Wells Containing Heavy Oil Based Muds
Authors: Brandl Andreas , Doan Angela Anh , Alegria Adriana Estela 
Published: October 2018

Abstract
Insufficient wellbore cleaning prior the cementing job is considered to be the biggest single factor leading to poor zonal isolation results. A mud-spacer-cement program with suitable fluid needs to be carefully engineered for the given wellbore conditions to improve cementing quality. We discuss optimum spacer design features which are critical for the successful cementation of deep deviated HPHT wells containing heavy oil based muds and review a simulated scenario. Advanced lab test methodologies beyond industry standards are utilized to model more accurately the given complex downhole conditions.
A simulated &gt;20,000 ft highly deviated wellbore was characterized by HPHT bottomhole conditions and the rheological performance of the cement spacer was critical to job success. The well needed a stable cement spacer that would not settle-out on the low side of the &gt;14,000 ft horizontal section, which would potentially put the well at risk. The 16.17 ppg mud required an even higher-density spacer system to clean it effectively. But conventional high-density spacer systems only compound the settling challenge and the well's anticipated bottomhole temperature of 350°F was expected to compromise any additives that might stabilize the fluid systems. Therefore a lab study about spacer stability was performed using a HPHT rheometer and the dynamic settling test – an industry standard which was actually established for cement slurries but not for spacer fluids. We found that a conventional spacer failed at 350°F by showing a rapid decline in rheology to almost zero viscosity and severe settling. To overcome the settling issue, provide stability, and maintain a sufficiently high rheology profile at given 350°F, we re-designed the spacer by using a modified biopolymer which shows a delayed hydration and viscosification over time successfully counteracting the destructive thermal effects.
The mud-spacer-cement fluid train was eventually optimized showing good fluid compatibility and maintaining within the narrow, 1.6 ppg margin that separated the pore pressure from the fracture gradient. The cementing job was designed using an advanced fluid displacement software, which predicted high mud removal efficiency under these challenging conditions. In order to enable proper mud displacement, the Friction Hierarchy—a key design factor that is often difficult to achieve under the extreme HPHT well conditions—was achieved with the new spacer concept.
Innovative Solution for High Temperature High Gas Rate Carbonate Well
Authors: Rashid Noor Hidayah , Fabian Oka , Johari M Raimi , Rosato Miguel , Samuel Orient Balbir , Idris M Faisal , Hong Ong Swee , Shaedin Muhamad Ridzuan , Loon Kweh Wei 
Published: October 2018

Abstract
Completing an over-pressured N field carbonate reef pinnacle gas reservoir with temperature above 170°C and relatively high concentration of CO2 and H2S can be tough. It gets tougher when in a high rate gas production, and the completion operation is managed in total losses condition. This paper presents the challenges, solutions and hindsight views of completion of high temperature high gas rate carbonate well with PMCD Top Kill Method via deployment of dual 7" and 4-1/2" liner string which are successfully accomplished in all 5 wells.
Learning from Experience: Real-Time H2S Monitoring System Using Fuzzy ART Unsupervised Learning
Authors: Alkamil Ethar H. , Abbas Ahmed K. , Flori Ralph , Silva Leonardo Enzo , Wunsch Donald C. , Chumkratoke Chatetha 
Published: October 2018

Abstract
Drilling boreholes through hydrogen sulfide (H2S) bearing formations such as Umm Er Radhuma and Tayarat Formations poses a critical challenge for the oil and gas industry in southern Iraq. In this era of increased concern for personal safety and environmental factors, the industry needs additional tools and methods for handling this deadly and corrosive gas. This paper describes how actual formation field data is entered into unsupervised learning software to train a H2S monitoring simulator to improve the drilling operators’ ability to detect H2S, analyse and then adjust mud pH to neutralize free H2S present in drilling fluids.
The H2S concentration measurements for five drilled wells in the Umm Er Radhuma and Tayarat fields in the South of Iraq used in a previous study are extended to include data from an additional 12 wells with 22 H2S events. This paper describes a real-time H2S simulator which consists of a computer interface kit implementing MATLAB code. The kit is provided with three LEDs (green, yellow, and red) representing different alert levels. The system monitors changes in H2S levels and triggers alarms depending on the levels. The setup of the alert levels for the simulator are adopted from both Health Safety Environment (HSE) policy and unsupervised vector quantization via Fuzzy Adaptive Resonance Theory (ART) neural network category ranges.
Results show that using Fuzzy ART to train the H2S simulator alert levels based on formation data leads to a smarter and more sophisticated alert system compared to the typical HSE set of alerts. Specifically, the Fuzzy ART derived alerts enable earlier detection of H2S events, faster response to changing H2S levels, and it computes workers’ exposure over time to H2S, to prevent excessive accumulation of H2S in the respiratory system.
The system demonstrates a smarter and more robust method for reducing risks to drilling personnel, rig equipment, and the environment while drilling in areas with H2S hazards.
Complete MPD Rigs: Is This the Future?
Authors: Gedge Ben , Yaw Norman , Postel David , Mardon Jeff , Frohlich Herbert , Nguyen Bot Viet , Thanh Ban Nguyen , Hong Duc Vu , Barbee Brian , Santos Helio , Gouldin David 
Published: October 2018

Abstract
There has been a lot of discussion around rigs with some capability to perform Managed Pressure Drilling - MPD - operations, with rigs having different permanent equipment installed. But all the rigs, somehow, would all be classified as ready to perform MPD operations. In order to clarify a bit this subject, this paper clearlt differentiates rigs with some permanent equipment installed, but the specialized MPD equipment and service are still provided by a service company, which is herein called MPD-Capable-Rigs, from rigs which have installed all the equipment needed for MPD, and the drilling contractor is the one offering the service, which is called Complete-MPD-Rigs. The objective of the paper is to discuss and illustrate what is involved in preparing an offshore and even onshore Complete-MPD-Rig. The paper also discusses the evolution of MPD, initially provided by service companies, with equipment needed to be rigged up and down on rigs, all the way to current stage where drilling contractors are providing the service directly. To achieve this stage the drilling contractors are equipping their rigs with the full MPD package and providing the service directly to the operators.
The paper describes the evolution of equipment installed and owned by the rig, from a few lines in the very beginning to a complete packge today. The movement towards the drilling contractor owning and offering the MPD service started with the deepwater rigs, but evolved to onshore rigs also. Today, both onshore and offshore drilling contractors Complete-MPD-Rigs.
Some examples of rigs with partial equipment installed are provided, illustrating the evolution of what a rig would own, until the most recent onshore and offshore examples of Complete- MPD-Rigs. This is definetly the future as it simplifies not only contractual and legal aspects but also improves a lot the competency of the rig crew and significantly reduces the problems of communications during an MPD operation when the equipment is not owned and provided by the rig.
The First CT Fiber-Optic Digital Implementation in Asia Pacific to Support Real-Time Perforation Depth Correlations and Enhance Wellbore Cleanout Efficiency in Horizontal Well, Thailand
Authors: Thawatthukool Prasen , Toempromraj Wararit , Sompopsart Suwin , Lilaprathuang Pipat , Weeramethachai Deephrom , Kiatrabile Thanita , Krisadasima Supakorn , Wattanasuwankorn Reawat , Pathmanathan Indran , Kritsanaphak Kritsana , Kangsadarn Arweephan , Daohmareeyor Tuanangkoon , Bohorquez Jorge 
Published: October 2018

Abstract
An onshore operator in Thailand faced the challenges of placing bridge plug and perforations with 2-m accuracy in a horizontal multi-stage interval prior to a fracturing operation and efficiently cleaning out the sand from the wellbore after fracturing. The solution selected to solve these two challenges was a fiber-optic-enabled coiled tubing (CT) string to support real-time plug set / perforation accuracy and sand cleanout, the first of this kind of operation in the Asia-Pacific region.
A fiber-optic cable was carefully pre-installed for slack management inside the CT string before the CT was stabbed into the well. The fiber cable provided real-time telemetry from a casing collar locator (CCL) downhole tool to a digital data interrogator on the surface to gain more accuracy in the horizontal section. Once precisely positioned, the CT was pressurized to activate the hydraulic setting tools for plug set and activating the firing head for perforation guns fired at the exact target depth. Using CT deployment, the operator also avoided the gun moving upward and becoming stuck in the well, which is a risk with a wireline and tractor application. The fiber-optics application also enhanced wellbore cleanout efficiency after fracturing with the advantage of real-time downhole circulating pressure.
The application goals were achieved as planned for this project, proving that CT can be used in this horizontal well section in conjunction with fiber optics. The fiber-optic real-time digital data from the downhole tool provided more accurate depth measurements for placing plug set and perforations, as well as monitoring bottomhole pressure to control smooth sand cleanout in the wellbore. This application also helped minimize the risk of operational failures due to the perforation gun moving upward after firing and the risk of the downhole tool becoming stuck (because CT can have larger pulling capacity than electric line operations). This new application also proved to be cost effective because CT fiber-optics applications can perform both perforation and sand cleanout operations, eliminating the requirement for electric line and tractor on location, saving both time and costs.
The advantages and benefits of using the CT fiber-optic digital application for placing bridge plug, perforations, and sand cleanout in horizontal well completions have shown significant improvement in terms of operational efficiency, cost savings delivered to meet the well operator's budget, and safety supporting multistage fracturing zones.
Increased Run Life in Progressive Cavity Pumps from Characterization of High Nitrile Elastomers in the Orinoco Oil Belt
Authors: Han M. J. , Guerra E.. , Rangel S. V. , Gamez I. B. , Delgado A.. 
Published: October 2018

Abstract
Progressive Cavity Pumping is the preferred artificial lift method in the extra heavy crude oil field Huyapari, located in the Venezuelan Orinoco belt. Typically, PCPs operating in saturated reservoirs such as Huyapari need to cope with significant amounts of free gas, often handling more than 50% of gas void fraction (GVF) at the pump intake. This, combined with production of large amounts of sand and exposure to aggressive fluids, poses vast challenges to the durability and performance of PCP elastomers. Consequently, a proper and engineered selection of elastomer materials has critical impact on overall pump run life.
This study describes a first experience in characterizing the effect of harsh fluids and solids on high acrylonitrile elastomers. Subject wells include those with high free gas and/or sand production rates, as well as those with elevated water cuts. The mechanical properties of elastomers were measured under controlled pressure and temperature conditions in order to define an optimum rotor-stator fit. Over 200 laboratory tests and several field experiments were conducted to allow for the most suitable selection of elastomer material regarding hardness and swelling behaviour. Aging tests and infrared spectroscopy were also used in these analyses to help reduce premature elastomer failures produced by hysteresis, explosive decompression and blistering. The results of the study indicate that PCP applications in wells producing high gas rates must avoid utilization of elastomers with a hardness below 65 shore A, because the increased gas permeability causes excessive swelling throughout the pump stator. In contrast, elastomers with hardness above 70-75 shore A proved to be more resistant to swelling and explosive decompression.
Benefits resulting from this study include an increased pump life cycle from 306 days in-hole in 2012 to 469 days in 2016. Premature PCP failure count decreased from 275 in 2012 (59% of wells in the field) to 153 in 2017.
Based on the results of this study, the authors propose new acceptance ranges for mechanical properties values (e.g. swelling performance and hardness) for PCP elastomer selection applied to extra heavy oil production in this field.
Analysis of Secondary and Tertiary High-Pressure Gas Injection at Different Miscibility Conditions: Mechanistic Study
Authors: Norouzi Hamidreza , Rostami Behzad , Khosravi Maryam , Afra Mohammad Javad 
Published: October 2018

Summary
In the current survey, the time required to rupture the water film shielding the oil as a result of oil swelling caused by the diffusion of dissolved gas in the water phase and trapped oil behind it has been investigated in porous medium at high pressure and temperature. To study the active mechanisms, the experiments have been conducted with two different types of injectants: carbon dioxide (CO2) and methane (with different solubility in water), under different miscibility conditions at equal reduced pressures. Experimental observations have been interpreted using theoretical studies. Furthermore, the time of water-film rupture has been identified in production data and matched by an analytical model. This time and its monitoring during various gas-injectant types and regimes under reservoir conditions have not been previously addressed.
The results show that water film reduces the performance of oil recovery by limiting the interface of oil and gas phases. Under such a condition, the best scenario is miscible gas injection because the gas can effectively swell the oil and rupture the water shield. At miscible and near-miscible conditions, the time required to eliminate the water film increases as the injectant solubility in water decreases; however, there is a negligible difference at the immiscible regime. The trend of oil-recovery curves after rupture of the water film shows that oil swelling is one of the main mechanisms involved in water-trapped oil recovery. These results suggest practical guidelines to better understand the effect of the water-shielding phenomenon in the field of tertiary gas injection. The outcome of this integrated study could effectively increase the knowledge of shielded oil recovery using different gas-injectant types under various miscibility conditions and could prepare the required basis for compositional simulation of waterflooded oil production during tertiary gas injection.
Carbon Dioxide Induced Corrosion of Carbon Steel X65 Exposed to Nitrite Aqueous Solutions
Authors: Vargas Silvia M. , Woollam Richard , Durnie William , Hodges Michael 
Published: October 2018

Summary
Nitrate used to control reservoir souring in oil fields contains nitrite impurities. Nitrite is a strong oxidizer, and when used in souring–treatment fluids, the flow path often includes carbon–steel piping. Vanadium, also an oxidizer, is at times found in oilfield–production streams that commingle with souring–treatment fluids. The interactions between nitrite and vanadium and their effects on carbon steel X65 corrosion were investigated.
The effect of nitrite on corrosion was investigated using synthetic brine to simulate produced water [rich in carbon dioxide (CO2), pH value of approximately 5] and seawater (negligible CO2, pH value of approximately 7). Tests were conducted with carbon steel X65 exposed to synthetic brine at 25, 60, and 80°C using a rotating cylinder electrode (RCE). The test results demonstrate the following:
The corrosivity of nitrite strongly depends on the pH level. Nitrite increases corrosion at pH of approximately 5 and is relatively benign at pH of approximately 7. Nitrite reduces to ammonium (thermodynamically stable in acid solutions), whereas vanadium(III) delays the formation of ammonium. Inhibited corrosion tests indicate that nitrite reduces the performance of the studied commercial corrosion inhibitors (CIs).
Particle-Transfer Between the Cyclone and Accumulator Sections of a Desander
Authors: Rawlins C. H. 
Published: October 2018

Summary
The flooded-core solid/liquid hydrocyclone, also called a desander, is often used in the upstream oil and gas industry to separate particulate solids from produced water. A desander incorporates a solid/liquid cyclone with an accumulation chamber connected to the apex. Solids collect in the accumulator for intermittent removal while the overflow is discharged continuously. With a flooded-core and static-liquid volume in the accumulator, the trajectory of a sand particle from the cyclone inlet to the apex is changed, compared with that in an open underflow hydrocyclone classifier. In this project, the transfer of solids from the cyclone to the accumulator section is studied, with emphasis on the limiting flux. The settling of solids from the cyclone to the accumulator follows a turbulent, hindered-settling relationship that can be approximated by models used for sedimentation hoppers. Measurement of the apex-flux rate shows a maximum choke point, beyond which solids will back up into the cyclone section. The limiting inlet solids concentration to reach this choke point is ≈2 g/L for small-diameter desanders. An apex-flux balancing system is proposed to overcome this flux-rate limitation.