bluuebunny/crossref_metadata_2025_split huggingface dataset:
Intelligent Prediction of Downhole Drillstring Vibrations in Horizontal Wells by Employing Artificial Neural Network
Authors: Saadeldin Ramy , Gamal Hany , Elkatatny Salaheldin , Abdulraheem Abdulazeez , Al Shehri Dhafer 
Published: February 2023

AbstractDuring the drilling operations and because of the harsh downhole drilling environment, the drill string suffered from downhole vibrations that affect the drilling operation and equipment. This problem is greatly affecting the downhole tools (wear and tear), hole problems (wash-out), mechanical energy loss, and ineffective drilling performance. Extra non-productive time to address these complications during the operation, and hence, extra cost. Detecting the drillstring vibrations during drilling through the downhole sensors is costly due to the extra service and downhole sensors. Currently, the new-technology-based solutions are providing huge capabilities to deal intelligently with the data, and machine learning applications provide high computational competencies to learn and correlate the parameters for technical complex problems. Consequently, the objective of this paper is to develop a machine learning model for predicting the drillstring vibration while drilling using machine learning via artificial neural networks (ANN) for horizontal section drilling. The developed ANN model was designed to only implement the surface rig sensors drilling data as inputs to predict the downhole drilling vibrations (axial, lateral, and torsional). The research used 5000 data set from drilling operation of a horizontal section. The model accuracy was evaluated using two metrics and the obtained results after optimizing the ANN model parameters showed a high accuracy with a correlation coefficient R higher than 0.97 and average absolute percentage error below 2.6%. Based on these results, a developed ANN algorithm can predict vibration while drilling using only surface drilling parameters which ends up with saving the deployment of the downhole sensors.
Real-Time Rig Less Intervention with a Catenary Coiled Tubing System to Perforate the Long Horizontal Section of a Well, Offshore Brunei
Authors: Leong Azemi , Abd Rani Rudzaifi Adizamri , Azizan Yusri , Yusoff Khairul , Idris Syahiran , Lim Hong Chean 
Published: February 2023

Abstract
A horizontal oil development well offshore Brunei had unwanted gas zones needing to be isolated and its oil zones reperforated. Limited deck space, riser length, long gun length, and a long horizontal section posed many challenges for executing the operation using conventional methods. To overcome these, a customized perforation and detonation gun system was used for efficient and safe deployment into a live well with Coiled Tubing (CT) to reach the target depth along with a Real-Time (RT) CT system, allowing more accurate depth correlation for the plug setting and perforation.
A Solution to the limited deck space was developed using an integrated RT catenary CT unit, pumping, and flowback package. This setup allows most of the equipment to remain on the vessel while transferring only minimal items to the platform and keeping the capability of pumping and safely managing the flowback from a live well. An adjustment to the injector jacking frame was also made by designing an extension that would safely increase the height for the gun length to be deployed while remaining able to withstand any strong weather. Additionally, software simulations were performed to verify that the longest perforating gun could successfully be deployed in and out of the live well. Due to the long target interval needing perforated, a gun deployment system was selected to reduce tripping time instead of a more traditional section-by-section method. With a ninety-meter gun length deployment in a single trip for the longest interval, this deployment method saved twelves trips compared to the more conventional approach. Overall, considering three intervals to be perforated, this system eliminated a significant number of trips for the whole project. RT CT integrated with sophisticated and reliable sensors guaranteed depth accuracy during the correlation process. These sensors delivered RT Gamma Ray (GR), Casing Collar Locator (CCL), pressures, compression, tension, torque, inclination, and temperature, fulfilling the requirement of achieving accurate depth control and overall RT monitoring of downhole conditions. The electrical firing mechanism allowed a more straightforward and safer firing process than the alternative of circulating a ball.
This project marked the first successful operation to perforate more than two hundred and fifty meters of target horizontal interval with three long perforating guns. This approach saved twelve runs compared to the more conventional method, which also needs additional correlation runs. The customized solution demonstrates that critical operations in long horizontal wells in challenging offshore environments can be successfully and safely executed.
Innovative Formation Testing Methods to Enhance the Field Development Plan: a Case Study in South-East Asia
Authors: Nakatani Akira , Cartwright Anthony , Copp Jonathan , Khunaworawet Tanawut , Daungkaew Saifon , Phan Linh , Kieu Viet , Babu H. Jagdeve 
Published: February 2023

AbstractIn early 2010s, two gas and gas condensate fields were discovered in a South-East Asia Basin. The Field Development Plan (FDP) was approved to develop both. After drilling several wells, the operator encountered complex challenges: (1) lower permeability reservoirs (2) complex HPHT subsurface structures (3) fluid identification, (4) reservoir understanding and connectivity. Formation evaluation, especially formation testers were therefore crucial for better reservoir understanding, to de-risk the FDP and maximize future productivity of the field.This paper will discuss formation evaluation and formation testing in this campaign which consists of more than 10 jobs. Firstly, proper pre-job design and planning was done based on reservoir fluid information and reservoir properties from the previous exploration campaign. Analytical and numerical simulation models were conducted to properly design the Formation Tester (FT) tool string: probe/packer types, pump rate, and displacement unit types. Later, logging operation procedure, real time monitoring, and communication protocol will be also discussed with lessons learned and best practices. This workflow has set another milestone for fit-for-purpose solutions to tackle the reservoir and operational challenges.In this campaign, apart from a new discovery, based on Downhole Fluid Analyzer (DFA) technology, we surprisingly proved different fluids in the deeper reservoirs. In addition, we were able to address reservoir connectivity, the main uncertainty in their FDP. This paper also discusses several innovative methods associated with FT technology to reduce uncertainties in the FDP such as:The FT selection to help obtain best reservoir data, even in the most challenging environments such as low permeability, uncertain reservoir fluids, HPHT, and complex subsurface structure. As no well test was planned, Interval Pressure Transient Test (IPTT) data was used to obtain zone permeability which was later used to calibrate petrophysical data and the dynamic reservoir model. The use of pressure and DFA data to understand reservoir connectivity. The comparison between DFA data and PVT lab results will be also discussed. The use of advanced reservoir simulation software to understand reservoir contact uncertainty and improve reserve estimation.From this work, we have learnt that collaboration between different teams and disciplines is most important for this to be a smooth and seamless operation. Innovation and sustainability workflows are always possible to adapt in order to achieve good results even in the most challenging environments.
Innovative Formation Testing Methods to Enhance the Field Development Plan: A Case Study in South-East Asia
Authors: Nakatan Akira , Cartwright Anthony , Copp Jonathan , Khunaworawet Tanawut , Daungkaew Saifon , Phan Linh , Kieu Viet , Babu H Jagdeve 
Published: February 2023

AbstractIn early 2010s, two gas and gas condensate fields were discovered in a South-East Asia Basin. The Field Development Plan (FDP) was approved to develop both. After drilling several wells, the operator encountered complex challenges: (1) lower permeability reservoirs (2) complex HPHT subsurface structures (3) fluid identification, (4) reservoir understanding and connectivity. Formation evaluation, especially formation testers were therefore crucial for better reservoir understanding, to de-risk the FDP and maximize future productivity of the field.This paper will discuss formation evaluation and formation testing in this campaign which consists of more than 10 jobs. Firstly, proper pre-job design and planning was done based on reservoir fluid information and reservoir properties from the previous exploration campaign. Analytical and numerical simulation models were conducted to properly design the Formation Tester (FT) tool string: probe/packer types, pump rate, and displacement unit types. Later, logging operation procedure, real time monitoring, and communication protocol will be also discussed with lessons learned and best practices. This workflow has set another milestone for fit-for-purpose solutions to tackle the reservoir and operational challenges.In this campaign, apart from a new discovery, based on Downhole Fluid Analyzer (DFA) technology, we surprisingly proved different fluids in the deeper reservoirs. In addition, we were able to address reservoir connectivity, the main uncertainty in their FDP. This paper also discusses several innovative methods associated with FT technology to reduce uncertainties in the FDP such as: The FT selection to help obtain best reservoir data, even in the most challenging environments such as low permeability, uncertain reservoir fluids, HPHT, and complex subsurface structure.As no well test was planned, Interval Pressure Transient Test (IPTT) data was used to obtain zone permeability which was later used to calibrate petrophysical data and the dynamic reservoir model.The use of pressure and DFA data to understand reservoir connectivity. The comparison between DFA data and PVT lab results will be also discussed.The use of advanced reservoir simulation software to understand reservoir contact uncertainty and improve reserve estimation.From this work, we have learnt that collaboration between different teams and disciplines is most important for this to be a smooth and seamless operation. Innovation and sustainability workflows are always possible to adapt in order to achieve good results even in the most challenging environments.
Sand Fill Clean-Out on Wireline Enables Access to Additional Perforation Zones in Gas Well Producer
Authors: Field David 
Published: February 2023

Abstract
An Australian operator wanted to explore options for wireline conveyed sand bailing in one of their offshore platform gas producing wells. The objective was to remove twenty-six meters of sand fill inside 9.625" production casing, with an internal diameter of 8.681". Due to the landing nipple at the end of the tubing, the minimum run-in-hole restriction of the production tubing string was 3.987".
To limit the number of clean out runs, the latest technology in e-line deployed suction tools with a 4.25" OD was chosen, which provided increased recovery volume over its smaller cousins, plus real-time surface control and monitoring. Because of the tool's overall diameter, the landing nipple also required milling to allow access. Therefore, a specially designed 4.412" mill bit was manufactured and run on a milling tool – a tool requiring tractor conveyance to provide weight-on-bit and counter the reactive torque.
As the well had low deviation, the subsequent clean-out toolstring was run standalone (without tractor). One of the key factors governing the feasibility of conducting this operation on e-line was the overall toolstring lengths, where the lubricator height was limited to approximately sixteen meters.
The e-line deployed milling technology – which produces a grinding action rather than cutting – successfully milled through the landing nipple and a ball catcher in four runs, thus increasing the internal diameter sufficiently to allow access for the clean-out toolstring. A well fluid column of about seven bar is required to enable operation of the suction tool. The clean out tool was configured with three bailer sections (seven max) for the first run, to determine sand recovery optimisation. Three different sizes of micron bailer filters are provided; prior knowledge of debris particle size is therefore advantageous. In this case, a slickline bailing sand sample had been recovered, which immediately aided filter choice. Seventeen bailing runs were conducted over five days (with the number of bailer sections increased to six), successfully recovering a total of 918 litres of sand, equating to about 2.4 tons. Ultimately, the process enabled perforation of two additional gas zones to increase production.
The e-line toolstring, consisting of six different sensors and robotic tools, made this a more controllable and inherently safer operation than coiled tubing methods, as well as having a smaller footprint with reduced environmental impact. Operational details, including job planning and lessons learned will be discussed in the extended abstract.
Rejuvenating Waterflood Reservoir in a Complex Geological Setting of a Matured Brown Field
Authors: Azman Mohd Fairuz , Tunku Kamaruddin Tunku Ahmad Farhan , Mohmad Nis Ilyani , Zulkafli Luqman Hakim , Salleh Khiril Shahreza , Bakar Rizal 
Published: February 2023

AbstractField A consists of multi stacked reservoirs in high geological complexity and heterogeneity setting, with waterflooding has been the secondary drive mechanism for the past two decades. However, in recent years, the field experiencing significant production decline that warrant immediate mitigation plan and action. Therefore, this paper highlights challenges and best practices in rejuvenating water injected reservoir to improve field production by integrating geological re-interpretation, data acquisition and analytical evaluation.The reservoir is defined in deltaic environment with complex fluvial reservoir architecture. Despite no indication of structural trap or compartmentalization, there is significant variation in reservoir performance across the field indicates lateral heterogeneity that is affecting the areal sweep efficiency. Poor production-injection allocation data due to commingled production, aggravated by tubing leaks have hindered for an optimum formulation of waterflood strategy in the past. As part of the mitigation plan, depo-facies definition and stratigraphy boundaries were further refined, guided by well and reservoir pressure performance. Besides, inter-well tracer injection implementation proved to be the game changer - unfolded hydrodynamic connectivity and flow path of injected water understanding, established actual producer and injector pairing, and identified poor or unswept areas. It was supported by comprehensive analytical water injection performance analysis including Hall's Plot, Chan's Plot, Jordan's Plot as part of the routine surveillance activities to trigger any non-conformance. More aggressive well intervention also helped to identify and rectify well issues.As the outcomes, there is opportunity to increase water injection rate by 30% field wide by reactivating idle wells, converting producers to injector, and maximizing the existing injection within the safe fracture limit. The subsurface risks on fracture gradient uncertainty and sweep inefficiency due to water cycling to be mitigated via injectivity test with gradual injection, close monitoring of liquid rate handling at surface, and pattern balancing between injectors and producers. The liquid rate is expected to be restored and sustained nearing the historical peak, hence improve field production and temper the decline.This paper presents the best practices to address the challenges in a matured waterflood reservoirs, considering the complex geology setting. Understanding of the flood pattern from tracer analysis, supplemented by producer-injection performance assessment and well integrity status validation enabled water injection to be ramped up at the right area in strategically and safely manner.
Generation of Sodium Hypochlorite from Produced Water
Authors: M. Shah M. Faris , M. Timyati M. Fittri , Tengku Mizam Tengku Muhamad Alif Luqman , Azaman Dzulkarnain 
Published: February 2023

AbstractThe major process in crude oil terminal was the separation of light hydrocarbon and water from crude using heat. The daily crude output capacity of a crude oil terminal is in between 90 and 100 kbd. The produced water from the separation unit will flow into the produced water tank before being delivered to the skimmer pits for further treatment. Following treatment, the effluent will be released into the ocean in accordance with the standards set by the Department of the Environment (DOE). Approximately 1,085,681 kl of water with a high concentration of chlorine were discharged by the crude oil terminal per year.With a high chlorine concentration in place, the large amount of produced water can be used to generate chloralkaline feed. Even if it is now crucial from an environmental standpoint because generated water is regarded as the most significant waste stream, there still needs to be a plan in place for the crude oil terminal to reuse or recycle the wastewater. A baseline analysis was carried out with the present wastewater volume to confirm that water reuse and recycling may provide value, protect the environment, and help the main company to realize its sustainability agenda. Increasing the amount of produced water and wastewater in operations, lowering reliance on outside water supplies, and ensuring the commercial viability of resources are other goals of this study.In this study, electro-chlorination (ECU), a water filtering process, and a test for free and total chlorine were all used to carry out experiment work utilizing the HACH method. These tests were performed to see out how much chlorine was present in the sodium hypochlorite solution that the ECU generates. The outcome showed that the electro-chlorination process would produce a more alkaline solution the longer it operated. It results from the electrolysis process, which increases the concentration of OH- ions in the solution.Laboratory testing is done to confirm that the produced water from the crude oil terminal can be used to electrogenerate hydrogen and sodium hypochlorite. The wastewater was subjected to three (3) tests, the first of which involved water filtration to remove suspended particulates, the second of which involved electro-chlorination using an electro-chlorination unit (ECU), which produced NaOCl as a product and H2 as a by-product. Finally, a dilution experiment is conducted to lower the concentration of the NaOCl solution so that it is within the range prior to the Free and Total Chlorine test. Using a Hach DR900 machine, the solution is then tested to determine the amount of free and total chlorine present in the effluent.
A Novel Seawater-Based Fracturing Fluid for Streamlined Logistics, Long-Term Scale Protection, and Enhanced Oil Recovery
Authors: Ke Linping , Yue Zhiwei , Slocum Andrew , Li Chunli , Larsen Travis 
Published: February 2023

AbstractSeawater-based fracturing fluid systems are well known for the economic and logistical benefits they provide, including unlocking a usable water source in locations that lack access to fresh water and eliminating the need for extra freshwater supply vessels at offshore wellsites. However, a common challenge with these systems is the formation of scale that results when the high content of sulfate in seawater contacts a barium-rich formation. Additional challenges include minimizing gel residue and mitigating water blockages that can negatively impact oil production after the fracturing treatment. To address these issues, a new seawater-based borate-crosslinked fracturing fluid, with integration of a phosphorus-free polymeric scale inhibitor (SI) and a flowback aid, was developed and evaluated for scale inhibition, oil displacement efficacy and rheological performance.The seawater-based fracturing fluid rheology and compatibility with a scale inhibitor at varying concentrations were studied in a rotational rheometer. Static bottle test was used to evaluate the long-term barite inhibition. Oil migration and displacement of the fracturing fluid through a column flow apparatus were investigated to demonstrate the synergistic effect of the scale inhibitor and surfactant on enhancing oil mobility through porous media.Addition of various concentrations of SI does not impair the fluid crosslinking, aging and breaking process, and provides effective scale inhibition over a six-month extended shut-in period. With respect to oil displacement, the frac fluids containing the scale inhibitor and surfactant at certain concentrations outperform the control samples without these additives or that only contained a single additive. It is shown that the seawater-based fracturing fluid has good stability under all shearing schedules and has quick shear recovery after exposure to high shear, indicating the fluid has excellent proppant carrying capacity.With integration of a polymeric scale inhibitor (SI) and a flowback aid, the seawater-based borate crosslinked fracturing fluid demonstrates reliable rheological performance, superior scale inhibition, and improved oil displacement with reduced water blockage due to the synergistic effect of combining these chemistries.The integrated fracturing fluid system designed for seawater operations not only provides a reliable fluid performance, long-term scale protection, and better oil recovery, but also significantly reduces logistical costs for offshore applications, especially for those requiring additional supply vessel support to transport frac fluid. All these aspects of the fluid system result in a reduced treatment cost, increased operational efficiency in time and process, reduced fluid waste, and lower CO2 emissions.
THE EXPRESSION OF POSSESSION IN SOME LANGUAGES OF THE EASTERN LESSER SUNDA ISLANDS
Authors: GrangÃ© Philippe 
Published: February 2023

The possessor-possessed, or â€œpreposed possessorâ€ syntactic order, has long been considered a typological feature common to many Eastern Lesser Sunda Islands, labelled either â€œCentral-Malayo Polynesian languagesâ€ or â€œEast Nusantara languagesâ€, although these groupings do not exactly coincide. In this paper, the syntax and semantism of possession in some languages of the Eastern Lesser Sunda Islands are described. There is a wide variety of possession marking systems in the Eastern Lesser Sunda Islands, from purely analytic languages such as Lio to highly flexional languages such as Lamaholot. The morphological contrast between alienable and inalienable possession is widespread among the languages of this area. The study focuses on Lamaholot, spoken at the eastern-most end of Flores, and the three neighbouring islands of Adonara, Solor and Lembata. This language has a complex possessive system, involving suffixes, free morphemes, a specific preposition, and possessive pronouns, along with person agreement and morpho-phonological features. Lamaholot can be considered a highly representative example of East NusantaraÂ languages.