bluuebunny/crossref_metadata_2025_split huggingface dataset:
PARASITE DIVERSITY OF <i>Hoplosternum littorale</i> FROM THE TIETí­Å -BATALHA RIVER BASIN, SOUTHEASTERN BRAZIL
Authors: PELEGRINI Larissa Sbeghen , VIEIRA Diego Henrique Mirandola Dias , LEITE Lucas Aparecido Rosa , GIÃO Thayana , AZEVEDO Rodney Kozlowiski de , ABDALLAH Vanessa Doro 
Published: October 2021

A total of 53 tamboatás, Hoplosternum littorale, from the Batalha River, São Paulo, southeastern Brazil, were examined between February 2014 to December 2016. Seventeen species of parasites were identified, and 961 specimens were collected . The richness of each community varied from one to seven species of parasites per fish. The metacercariae of Diplostomum lunaschiae showed higher prevalence and mean abundance, being the core species. Gyrodactylus sp. obtained a higher mean intensity value. Aporocotylidae gen. sp. showed a significant negative correlation between its abundance and the standard host weight and length, while Spiroxys sp. showed a significant negative correlation between its abundance and the host weight. Batalha River has importance as a maintainer of local biodiversity with a relevant contribution to the knowledge of freshwater biodiversity in the State of São Paulo. Gyrodactylidae gen. sp., A. mordax, Aporocotylidae gen. sp., D. lunaschiae, Diplostomidae gen. sp. 1, Contracaecum sp., D. renale, Porrocaecum sp., Pseudocapillaria sp. 1, Pseudocapillaria sp. 2, S. contortus, Oligobdella sp., and L. cyprinacea are parasites mentioned for the first time in H. littorale. Aporocotylidae gen. sp., Gyrodactylidae gen. sp., and Oligobdella sp. are new species in process of taxonomic description by the authors of the present study.
A Practical Approach to Manage Top-Hole Collision Risk in Crowded Fixed Platform: Implementation in Offshore East Kalimantan
Authors: Feizal Aulia Hamdani , Pribadi Made Allan , Riambomo Eka Pambudi , Durachman Ridwan 
Published: October 2021

Abstract
The requirement of drilling in very close proximity to adjacent wells in surface hole section has been common as field become more crowded. This is true especially in offshore mature field where the last wells are drilled on a dense platform. In Santan Field, East Kalimantan, conductor pipes were driven between the existing wells since sidetrack or platform extension options were not available at the time while there are still opportunity for infill and step out wells.
This situation introduces challenges on well construction in term of collision avoidance since the spacing between the wells are tight from surface point. The distance between slots is as low 1 meter from center-to-center, and 0.64 meter between wall-to-wall. Directional works was also required at shallow depth to kick of the well as per trajectory requirement.
The risk of unplanned intersections with adjacent well can lead to financial loss, personnel safety as well as environmental issue. A comprehensive risk assessment were conducted during the planning phase as the safety of drilling operation has been one of the main concerns. Mitigations plan were then formulated with the objectives to manage the negative consequences to acceptable level.
During the planning phase, detail anti-collision procedure was executed to evaluate the collision risk. On the field, several activities were carried out on adjacent wells prior to rig move in as mitigations measure: 1) Rig less resurvey, 2) Well integrity inspection, and 3) Well barrier placement. While drilling, following strategies were performed: 1) GWD utilization, 2) Monitoring on subject and adjacent wells, and 3) Collision-tolerant drilling bit application
The all-surface hole were drilled safely without any HSE or reliability issue. No major indications of well collision were observed. However, the drilling time took bit longer than usual performance due to drilling controlled manner for anti-collision precautions.
This paper explain how well collision mitigations was implemented in Santan Field, East Kalimantan, which can be a reference for further drilling as a successful case of top-hole drilling on a dense fixed platform. The method is expected to gain economic value, which is notably beneficial in mature field.
First Application of Micro Coiled Tubing in Indonesia at Offshore Mahakam
Authors: Marindha Rantoe , Kurniawati Pratika Siamsyah , Pancawisna Gerardus , Hidayat Reyhan , Dahnil Gitani Tsalitsah , Umar Khalid , Rahman Risal , Alfarisy Nasrulloh , Marsudiono Eko , Chhin Clement 
Published: October 2021

Abstract
In order to answer the future challenges associated with offshore logistics, minimalist platform and job simplicity, smaller footprint of coiled tubing set is required for pumping job.
Although coiled tubing (CT) is one of the most efficient deployment method for multiple wellsite operations and various objectives. Often it is difficult to capture all the benefits of its application in some offshore wells. Limited crane capacity and deck space at the platform often provide challenges to efficiently execute a CT operation. Minimalist and crowded platforms may not allow conducive condition to set up a conventional CT system.
As part of continuous improvement in Well Intervention, smaller size of CT called Micro CT is deployed to unload the completion fluid using nitrogen pumping. This is to provide sufficient drawdown prior to clean up or perforation jobs.
Micro CT is a small coiled tubing typically with 1" outside diameter and 10,000 ft length. It is approximately half the weight and a third smaller compared to the conventional CT. The start-up project of 1st Micro CT job in Indonesia is commenced with unloading Job in Bekapai and South Mahakam wells. Five (5) unloading job are successfully performed within allocated time frame and budget. There were no major safety issues recorded. Total of 60% cost saving was generated from the reduced mobilization trips of supply boat while 40% cost saving is from improved diesel consumption efficiency. From operational aspect, less annular friction can be achieved and led save up to 35% in N2 consumption. Moreover, it saves10 – 20% rig up time in comparison to conventional CT. On top of that, those 5 unloading jobs was completed with liquid unloading efficiency of more than 70% from the target.
This paper will elaborate the experience of an Asset Operator in deploying 1st Micro CT application safely and will discuss in detail some of the measurable milestone achievement from the project.
Safeguarding CO2 Storage by Restoring Well Integrity Using Leakage Rate Modeling LRM along Wellbore in Depleted Gas Fields Offshore Sarawak
Authors: Patil Parimal A. , Chidambaram Prasanna , Ebining Amir M Syafeeq B. , Tiwari Pankaj K. , Picha Mahesh S. , Abdul Hakim Hazlan , Das Debasis P. , B A Hamid Khaidhir , Tewari Raj Deo 
Published: October 2021

Abstract
Ensuring long-term integrity of existing plugged and abandoned (P&A) and active wells that penetrated the selected CO2 storage reservoir is the key to reduce leakage risks along the wellpath for long-term containment sustainability. Restoring the well integrity, when required, will safeguard CO2 containment for decades. Well integrity is often defined as the ability to contain fluids with minimum to nil leakage throughout the project lifecycle. With a view to develop depleted gas fields as CO2 storage sites in offshore Sarawak, it is vital to determine the complexity involved in restoring the integrity of these P&A wells as well as the development wells. Leakage Rate Modeling (LRM) was performed to identify and evaluate the associated risks for designing the remedial action plan to safeguard CO2 storage site.
The P&A wells in the identified depleted gas fields were drilled 35–45 years ago and were not designed to withstand high CO2 concentration downhole conditions. Corrosive-Resistant Alloy (CRA) tubulars and CO2 resistant cement were not used during well construction and downhole pressure and temperature conditions may have further degraded the material strength and elevated the corrosion susceptibility. As a proof of concept, single well was selected to assess the loss of containment along the wellbore and to determine the complexity in resorting the well integrity, multiple scenarios were considered in LRM and composite structure and barrier parameters were assigned to estimate possible leakage pathways. Detailed numerical models were simulated for estimating leakage from reservoir to the surface through possible leakage pathways. Risks were identified and remedial action plan was designed for restoring well integrity. Post remedial plan covers Marine CO2 dispersion modeling to design comprehensive monitoring and mitigation plan for potential CO2 leakage in the marine environment.
This study summarizes the unique challenge associated with estimating well integrity and re-entering existing P&A wells. Leakage rate modeling along these wells involves uncertainties but when carried out with realistic parameters, it can be used as a predicting tool to determine the nature and complexity of leakage. Integrating with site survey results for any indication of gas bubbling, decision can be made to restoring the well integrity. The paper outlines the detail strategic options to safeguard CO2 storage by restoring well integrity using LRM and integrating with marine CO2 dispersion modeling. Assessing well integrity of P&A wells on individual basis, risk is assessed and identified. Proper remedial actions are proposed accordingly. Quantification of all the uncertainties involved needs to be conducted that may affect long-term security of CO2 storage site.
Improvement of Rheological and Filtration Properties of Water-Based Drilling Fluids Using Bentonite-Hydrothermal Carbon Nanocomposites Under the Ultra-High Temperature and High Pressure Conditions
Authors: Zhong Hanyi , Guan Ying , Qiu Zhengsong , Feng Jie , Liu Wenlei , Wan Yuan , Zhang Yubin 
Published: October 2021

Abstract
With the depletion of the conventional shallow oil/gas reservoirs and the increasing demand for oil and gas, deep drilling become more and more essential to extract the oil/gas from deep formations. However, deep drilling faces many complex challenges. One of the complexities is the degradation of polymers and flocculation of bentonite particles, leading to hardly control the rheological and filtration properties of water-based drilling fluids, especially under ultra-high temperature and high pressure (HTHP) conditions. Therefore, an experimental investigation is performed to study how bentonite-hydrothermal carbon nanocomposites will influence the rheological and filtration properties of water-based drilling fluids under ultra-HTHP conditions.
Bentonite-hydrothermal carbon nanocomposites are proposed as non-polymer additives to solve the ultra-HTHP challenge in water-based drilling fluid. The nanocomposites are synthesized by facile hydrothermal reaction, in which biomass starch and sodium bentonite are used as the precursor and template, respectively. In this study, the effect of the nanocomposites on the rheology and filtration properties of water-based drilling fluid are investigated before and after hot rolling at 220 °C and 240 °C.
The structure characterization indicates that carbon nanospheres can successfully deposit on the bentonite surface after hydrothermal reaction and finally form as nanocomposites. The elemental carbon content, zeta potential and particle size distribution of the nanocomposites could be adjusted according to the reaction conditions. After thermal aging at 220 °C and 240 °C, addition of nanocomposites can improve the rheological properties significantly where a stable and minor change of rheological properties is observed, which is desirable for ultra-HTHP drilling. Regarding filtration control, after adding 1.0 wt% nanocomposite materials, the filtration loss is reduced by 41% and 44% respectively after aging at 220 °C and 240 °C, which is better than the conventional natural materials that lose their function in this case. The identification of microstructure shows that the hydrothermal reaction endows nanocomposites with a unique surface morphology and an improved surface charge density. The interaction between nanocomposites and bentonite particles forms a rigid connection network, which is the main mechanism to facilitate effective rheology and filtration control under ultra-HTHP conditions.
The green and facile synthetic routes and environmentally friendly features of the nanocomposites, coupled with the excellent performance in ultra-HTHP rheology and filtration control, indicate that the nanocomposites have a high promise for water-based drilling fluid in ultra-HTHP drilling. Moreover, it provides a new way to design high performance additives with high temperature stability.
Designing the Maximum Permissible Production Cost of Oil and Gas Project Using Control Chart Analysis
Authors: Abdul Azizurrofi Ahmad , Setya Buana Yosef 
Published: October 2021

Abstract
During the period of 2005 to 2020, the oil prices reached the highest level in 2008 (99.67 US$/bbl) and the lowest level in 2020 (39.16 US$/bbl). The fluctuation in oil prices will affect the expenditures for both investment and production in oil and gas projects. Based on this condition, the standardization of the costs of investment and production is needed to help the government and contractor in estimating the costs needed in an oil and gas project.
As of December 2018, 471 projects (POD) have been approved by the government of Indonesia. All of them are projects that produce oil (oil projects) and gas (gas projects). In these projects, details of operating (Production) costs are included in the economic evaluation.
For the purpose of this paper, Indonesia was divided into 2 areas (Onshore and Offshore). Each of the areas had 2 different types of projects (oil project and gas project). Then, to collect the data related to the cost of production and reserves, the maximum cost of production per BOE was calculated and produced using the Control Chart Analysis method. Lastly, the result was distributed to those aforementioned areas.
Based on the evaluation and analysis of the cost of production from 273 oil and gas projects in Indonesia, oil and gas projects in Indonesia are economically acceptable as the maximum cost of production (US$ per BOE) is still far below the oil price (~65 US$/BBL). The following is the estimated Maximum Cost of Production generated in Indonesia: Onshore – Oil Projects (28.00 US$/BOE), Onshore - Gas Projects (12.27 US$/BOE), Offshore - Oil Projects (21.20 US$/BOE), Offshore - Gas Projects (15.95 US$/BOE).
Finally, this paper will show how to produce the maximum cost of productions per BOE using control chart analysis. This paper is expected to provide references (method) for the government of Indonesia in giving approval to the cost of production proposed by contractors. In addition, this paper may provide contractors with a quick look at oil and gas industry in Indonesia, especially those who plan to invest in Indonesia. It may also help them create their petroleum exploration and exploitation strategy in Indonesia if they take this information into consideration, which will benefit both the government and contractors.
Energy Transition in Oil and Gas Companies: A Case Study in the Colombian Hydrocarbons Sector
Authors: Plazas Niño Fernando Antonio 
Published: October 2021

Abstract
The conjunction between energy transition and oil and gas companies sets a significative question related to the role that these companies should play to respond to the gradual but continuous change in the worldwide energy system and the challenge of migrating from a fossil fuel-based structure to a green energy-driven economy with zero emissions of greenhouse gases. In this context, this paper enables to illustrate the main actions and strategies implemented by oil and gas companies to address the energy transition through a case study involving the most important Colombian company in the sector. Likewise, the work spotlights the relevance of implementing policies aimed at the transformation of oil and gas companies into integrated energy companies. Finally, an analysis framework is proposed to study the performance of oil and gas companies in the area of energy transition as a contribution for future research.
A Case Study on Field F Multiphase Flow Meter: How is it Better than a Conventional Test Separator?
Authors: Chang Li Si Claire , Johing Fedawin , Wong Yoon Chiang , Mohd Fauzi Nur Melatee Binti , Mohamad Ahmad Muzakkir Bin , Chiew Kwang Chian , Chaw Kit Teng 
Published: October 2021

Abstract
Multiphase flow meters (MPFM) have been known save costs for new installations, are compact and as effective as a test separator. Field "F" is a green field with 2 wells and has been producing since 2018 from the same reservoir. The test facilities consist of an MPFM, and F flows to a hub called Field "G". Towards Q2 of 2019, there was a significant increase in production rates from both wells without any changes to surface choke size and without enhancement jobs performed. Added to that, reservoir pressure showed steady depletion. Daily production allocation for F showed lower than usual reconciliation factor when combined with G hub production. This suboptimal allocation raised doubts about the MPFM well test readings which launched a full investigation into the accuracy of the meter.
From the offshore remote monitoring system, the first suspect was the increased inlet pressure causing parameters to be out of the MPFM operating envelope range. However, after further checking, there were other pressing issues such as faulty transmitter, and low range sensors. As these issues were being dealt with amidst the COVID-19 pandemic, the process to fix the meter was longer than usual. Rectification involved troubleshooting the MPFM post performing Multi Rate Tests, back allocation check to hub production and PROSPER/GAP model matching to check on the credibility of the well tests. These efforts were made due to budget cuts, as there was no advantage to bring onboard an entire well test package (separator) to test the F wells.
Post several rectifications, the liquid, gas and oil rates were within 10% difference from allocation meter back allocation and PROSPER model calculation. Reconciliation factor for field G has also increased to normal range of 0.92 to 0.95. However, the rectification also showed a significant drop in metered rates, proving that the MPFM was indeed generating incorrect well tests since Q2 2019. The drop was higher than 30% in gross production rates which lead to a better understanding of the reservoir, and corrections to be made to dynamic models for any future development projects. This hence proves that even with the similar reservoir properties in both wells, the MPFM well tests still require vigorous checking and should not be treated in the same way as a test separator.
This paper will describe the efforts by surface and subsurface faculties to ensure the quality of well tests from the MPFM. For future projects considering the MPFM installation, best to frequently quality check the MPFM well test figures with a test separator. However, if that option is not feasible, the efforts in this paper can act as a guide for the field.
A Novel Self-Photodegradation Drilling Fluids Under Near-Infrared Light Irradiation with Preferable Wellbore Stability
Authors: Jin Jiafeng , Lv Kaihe , Sun Jinsheng , Bai Yingrui , Liu Jingping , Wang Jintang , Huang Xianbin 
Published: October 2021

Abstract
The ever-mounting drilling operations of the petroleum industry has been accompanied by tremendous wasted drilling fluid, Polycyclic Aromatic Hydrocarbons (PAHs) in which pose a huge threat to the health of human and ecosystem. Varying approaches have been proposed to remediate the damage caused by wasted drilling fluid, among which photocatalysis has been one of the most promising approaches for organic contaminants removal. The latest investigation shows that Bi2WO6 decorated on hydrophobic CNT can remove up to 80 % organic contaminant within a short time, exhibiting a preferable photocatalytic performance. Moreover, this hydrophobic CNT can play a vital role in stabilizing the wellbore due to its excellent water repellent. The objective of the study was to find out the effect of Bi2WO6 modified hydrophobic CNT on the PAHs photodegradation and wellbore stability in the process of drilling.
Bi2WO6 as a near-infrared driven photocatalyst has attracted worldwide attention due to its preferable oxygen vacancy and quantum efficiency. However, the application of Bi2WO6 was impeded by the low migration efficiency of photo-generated carriers. The combination of Bi2WO6 and composite with good conductivity has been an effective method to resolve this problem. The instability of wellbore caused by shale hydration during oil and gas drilling operations also brings a huge challenge. In this study, a photocatalyst with wellbore stabilization capacity is achieved by hydrophobic CNT modified via Bi2WO6 sheet with nano-size. The fluid loss and wettability property were measured to evaluate the wellbore stabilization capacity of this novel agent. Meanwhile, photodegradation experiments and pathway analysis were conducted to evaluate the effect of photodegradation by Bi2WO6/CNT on the organic contaminants.
Data of photodegradation indicated that the PAHs can be degraded up to 80% after treated by Bi2WO6/CNT, the migration efficiency of photogenerated carriers improved significantly. A slight decrease in fluid loss and distinctive increase in viscosity can be observed after treated with 0.3% Bi2WO6/CNT solution. The results of the rheology test verified that the photocatalyst has little effect on the rheological properties of drilling fluid. The result of SEM indicated that this novel Bi2WO6/CNT composite with a bombax structure can absorb preferentially organic contaminants, which is good at in-situ photodegradation and prevention of water invasion.
To sum up, PAHs in wasted drilling fluids can be photodegraded by the novel Bi2WO6 nano-sheet modified CNT, and the stability of wellbore can also be significantly enhanced due to wettability alteration.