Drilling Activity Research Articles

Karst geomorphology analysis for geohazard assessment via seismic relief and dip attributes in Jx carbonate field, Central Luconia Province, Malaysia

Carbonate reservoirs in the Central Luconia Province of Malaysia underwent significant karstification during the Miocene. Such features have a detrimental impact on drilling operations, as has been reported for over 40 years in this province. This implies that the karst architecture and geometry may exhibit potentially high-risk behaviours during drilling activities, necessitating a thorough investigation of the features. This study aims to achieve several objectives using Jx field subsurface data, i.e., 3D seismic data and well data, including (1) analysing the interrelationship between karsts and faults, (2) examining the appropriate and effective attributes for analysing the geomorphology of the karst surfaces, and (3) conducting comparative and analog studies to gain a comprehensive understanding of karst formation and characteristics. This research attempted to determine the dimensions and extent of the faults and karsts, which were discovered to be highly connected, and this endeavor is critical for assessing the potential hazardous risk features within the platform. The major fault lineaments that bound the study field were interpreted using the Automatic Fault Extraction (AFE) module application combined with the manual fault-picking technique in the PaleoScan 2022 software. Four main horizon surfaces within the carbonate interval were selected for evaluating karst geomorphology using appropriate seismic attributes, as geomorphology is an important subject that requires serious attention, particularly when determining low-risk regions for drilling programs. Two attributes were extracted from the horizon surfaces: seismic relief and dip attributes, which efficiently distinguish the karst features and define the structural morphology of karsts. Dendritic karst networks, as well as karst collapses or sinkholes, are the most common karst features observed. These features exhibit discontinuity form and synclinal expression (high dip magnitude) when viewed in seismic and using the applied attributes. The comparative and analog study was conducted in Niah Caves, Miri, Sarawak, Malaysia, using karst interpretation employing digital elevation model (DEM) maps and fieldwork. Most of the delineated karst features observed on the DEM map of the Niah Caves are similar to those discovered in the Jx field; however, their dimensions vary between the two carbonate buildups.

Enhancing Pronunciation Skills of Diploma Students at Bangladesh University of Business and Technology through Oral Drilling: A Comparative Study of Pre- and Post-Exposure to Accurate English Sounds among ESL Learners

The purpose of this study is to investigate the efficacy of oral drilling activities for improving phonetic skills at the diploma level at the Bangladesh University of Business and Technology. Data were gathered from 200 Bangladeshi students who were purposefully chosen, who speak Bangla as their first language, and who utilize English as a second or foreign language for academic purposes using qualitative methodology. A self-developed Likert-scale structured questionnaire was used to analyse students’ understanding of their learning experience, and pre- and post-usage pronunciation tests were conducted in conjunction with reading exercise tests for phonetic improvement. This study provides important insights into ESL pedagogy in Bangladesh and has the potential to shed light on ODA as a didactic approach used in EFL contexts, which offers more appropriate curriculum-based implications for oral practice that may improve the Pronunciation skills of students.

A supervised machine learning model to select a cost-effective directional drilling tool

With the increased directional drilling activities in the oil and gas industry, combined with the digital revolution amongst all industry aspects, the need became high to optimize all planning and operational drilling activities. One important step in planning a directional well is to select a directional tool that can deliver the well in a cost-effective manner. Rotary steerable systems (RSS) and positive displacement mud motors (PDM) are the two widely used tools, each with distinct advantages: RSS excels in hole cleaning, sticking avoidance and hole quality in general, while PDM offers versatility and lower operating costs. This paper presents a series of machine learning (ML) models to automate the selection of the optimal directional tool based on offset well data. By processing lithology, directional, drilling performance, tripping and casing running data, the model predicts section time and cost for upcoming wells. Historical data from offset wells were split into training and testing sets and different ML algorithms were tested to choose the most accurate one. The XGBoost algorithm provided the most accurate predictions during testing, outperforming other algorithms. The beauty of the model is that it successfully accounted for variations in formation thicknesses and drilling environment and adjusts tool recommendations accordingly. Results show that no universal rule favors either RSS or PDM; rather, tool selection is highly dependent on well-specific factors. This data-driven approach reduces human bias, enhances decision-making, and could significantly lower field development costs, particularly in aggressive drilling campaigns.

Talk green, act brown: Transition risks and drilling investments of U.S. upstream oil and gas firms

AbstractThis paper explores the relationship between upstream oil and gas firms' proactiveness in addressing climate change transition risks and their drilling investments. We propose that due to limited capabilities to transition to renewable energy, these firms may strategically display proactiveness to greenwash their intentions to increase drilling activities. Leveraging a unique dataset comprising manually collected information on upstream firms' drilling investments, we find empirical evidence supporting our hypotheses. Specifically, firms showing greater proactiveness toward transition risk during earnings calls paradoxically increase their drilling investments. Additionally, high oil prices negatively moderate this relationship by creating a lucrative environment that benefits stakeholders, such as shareholders and investors, and simultaneously alleviates internal resource constraints, thereby reducing the need for greenwashing. This study contributes to the literature by illustrating how firms, under significant societal pressure but lacking transition capabilities, employ greenwashing tactics to obscure their investment activities.

Influencing Factors and Model of Shallow Gas Enrichment in the Quaternary Sediments of the Qiongdongnan Basin, South China Sea

Investigating the primary influencing factors that regulate the enrichment of shallow gas not only deepens our understanding of the rules governing shallow gas enrichment in deep-ocean environments but also has the potential to enhance the success rate of locating shallow gas reservoirs. Recent drilling activities in the LS36 gas field located in the central Qiongdongnan Basin have revealed a substantial shallow gas reserve within the sediments of the Quaternary Ledong Formation, marking it as the first shallow gas reservoir discovered in the offshore region of China with confirmed natural gas geological reserves surpassing 100 billion cubic meters. However, the formation mechanism and influencing factors of shallow gas enrichment remain elusive due to the limited availability of 3D seismic and well data. This study employs seismic interpretation and digital simulation to decipher the dynamics of shallow gas accumulation and utilizes the carbon isotope composition of methane to ascertain the origin of the shallow gas. Our results show that the shallow gas is primarily concentrated within a large-scale submarine fan, covering a distribution region of up to 2800 km2, situated in the deep-sea plain. The δ13 C1 methane carbon isotope data ranges from −69.7‰ to −45.2‰ and all δ13 C2 values are above −28‰, suggesting that the shallow gas within the Ledong Formation is derived from a mix of biogenic gas produced in shallow strata and thermogenic gas generated in deeper source rocks. The results of gas sources, seismic profiles, and digital simulations suggest that thermogenic gas originating from the Lingshui and Beijiao sags was transported to the Quaternary submarine fan via a complex system that includes faults, gas chimneys, and channel sands. The mass-transported deposits (MTDs) in the upper reaches of the submarine fan have effectively acted as a seal, preventing the escape of shallow gas from the fan. Therefore, the factors contributing to the enrichment of shallow gas in the Qiongdongnan Basin include the presence of favorable submarine fan reservoirs, the availability of two distinct gas sources, the effective sealing of MTDs, and the presence of two efficient transport pathways. A conceptual model for the accumulation of shallow gas is developed, illuminating the complex formation–migration–accumulation process. This study underscores the importance of aligning multiple influencing factors in the process of shallow gas accumulation, and the suggested accumulation model may be pertinent to shallow gas exploration in other marginal sea basins.

Enhancing Detection and Mitigation of Toxicity in Marine Biota from Drilling Activities

The growing demand for petroleum-based energy has significantly contributed to environmental pollution, particularly in the oil mining industry. This study aims to evaluate the toxicity of oil drilling mud on marine biota, using tiger shrimp (Monodon peneus) as bioindicators. The shrimp were exposed to various mud concentrations (100%, 50%, 25%, 12.5%, 6.25%, 3.25%, 1.25%, and 0%) and observed over time intervals of 0, 24, 48, 72, and 96 hours. The methodology involved direct observation of the shrimp's survival rates at each mud concentration. The results revealed a significant decline in survival rates at higher mud concentrations, with a strong positive correlation (r = 0.81) between mud concentration and toxicity. The pH levels remained stable and alkaline (7.81–8.28), while turbidity at lower concentrations (6.25%) was within acceptable limits after 96 hours, with a strong correlation (r = 0.73). These findings underscore the importance of stringent monitoring and management of drilling mud disposal to safeguard marine ecosystems, aligning with Sustainable Development Goal (SDG) 14: Life Below Water.

Outer spiral drill rod lunar soil sampling resistance moment simulation study

Abstract The task of unmanned automated sampling of China’s lunar exploration is to bring back lunar soil samples with a certain depth, and sampling of external auger drill pipe is the best way. The power and moment size of the lunar surface is limited, so a special design is required. In this paper, a unique structural model of a double-auger drilling tool is designed. It is a movement analysis of lunar soil and drill pipe. We use simulated lunar soil simulations and experiments. The Hertz-Mindlin slip-free model in the discrete element software EDEM was used for numerical simulation. Given the disadvantage of the large amount of computation of discrete elements, the “embedding simulation method” proposed in this paper reduces the amount of computation. When drilling 0.4m and 1m under lunar and earth gravity, the magnitude and influence of drill pipe rotation and vertical velocity on the drag moment were analyzed. We provide the relevant technical parameters of the real unmanned drilling activities on the lunar surface. Through simulation, the rationality parameters of several groups of drill pipe drilling are obtained to ensure the smooth progress of drilling.

Determination of Rock Properties Based on Electrical Resistivity Tomography (ERT) in Taebenu, Kupang, East Nusa Tenggara

Determining rock properties is very important for various needs in engineering design. It requires samples of soil and rock that are representative enough for laboratory test. The effort to obtain rock properties through laboratory testing is arduous, therefore, it is anticipated that geophysical technique may be able to ease the process without reducing the quality of data. This research aims to determine rock properties based on resistivity. The rock properties data (stength, wet density, moisture content) was obtained through laboratory test on soil and rock samples from a drilling activity, while the resistivity data was obtained by using geoelectric measurement at the drilling locations as the trajectories. There were 10 boreholes with the depths varying between 30-100 m, while geoelectric surveying depth of investigation reached to about 80 m with a 500 m trajectory. The research was conducted that the study area is covered with Quaternary deposits which are mainly consist of clay and pebble sediments. A statistical method was performed to analyze the relationship between rock properties and resistivity. The result shows that in Quaternary rocks, there is sufficient evidence to conclude that there are significant linear relationships between resistivity and strength as well as natural moisture content, but not for wet density. This approach to the relationship of resistivity and rock properties can be utilized in geotechnical analysis for various purposes. The results of this analysis can be used as a reference when carrying out any future geotechnical analysis by combining resistivity measurements within the same study area.

Exploring source-specific ecological risks of PAHs near oil platforms in the Yellow River Estuary, Bohai Sea

The Yellow River Estuary (YRE) is one of highly remarkable regions profoundly impacted by human activities, with numerous oil platforms dispersed throughout. In this area, offshore oil exploitation may pose significant ecological risks. To comprehensively evaluate the quantitative impacts of oil field exploitation on the marine coastal ecosystem, this study investigated the occurrence, sources, and ecological risks associated with 16 polycyclic aromatic hydrocarbons (PAHs) in seawater and sediment near oil platforms in the YRE. We found that 1) The concentrations of PAHs decreased from the surface seawater to sediments; 2) The ecological risk level of PAHs in seawater exceeded that in sediments; 3) terrestrial sources (combustion), rather than offshore oil drilling activities, significantly influenced regional ecological risks through processes of atmospheric deposition and surface runoff. These findings provide essential data for future estuarine research efforts while supporting mitigation measures aimed at addressing marine environmental pollution related to oil production activities.

Application of Hydrothermal Synthesized Titanium Dioxide-Doped Multiwalled Carbon Nanotubes on Filtration Properties-Response Surface Methodology Study.

The success of any drilling activity mainly depends on the characteristics of the drilling fluid. Therefore, a high-performance drilling fluid is substantial for any drilling operation. During overbalance drilling operations, the drilling mud invades the permeable formations and causes the loss of circulation, which is responsible for nonproductive time events. Hence, the filtration characteristics of the drilling mud are an imperative property. The purpose of this study is to evaluate the filtration characteristics of water-based mud systems in the presence of polyanionic cellulose (PAC) and multiwalled carbon nanotubes (MWCNTs)/TiO2 nanoparticles. The nanoparticles were synthesized by using the hydrothermal technique. For the first time, a composite of MWCNTs and TiO2 has been utilized as a fluid loss control additive in the petroleum sector, marking a significant development in the field. The filtration properties of water-based mud were assessed at two concentrations (0.35 g and 3.5 g). Furthermore, based on the two levels (concentrations) and two factors (particles), the novel application of the central composite response surface design of experiment (CCD) was implemented. The results showed that the predicted model from CCD was in good agreement with the filter press experimental result with R 2 = 0.8446. Furthermore, based on the ANOVA analysis, the concentration of MWCNTs/TiO2 nanoparticles was the most significant parameter with p-value < 0.05. In addition, 10 out of 13 experimental points fall under the ±10% error window, thus indicating a higher accuracy of the regression model. The 2D interactive plots further show that the concentration of PAC is insignificant and has no considerable influence on fluid loss control, which was also validated by p-value > 0.05. The performance of MWCNTs/TiO2 nanoparticles is superior to PAC because these nanodimension particles plug the pore-spacing and block the permeation channels on the filter paper. However, the PAC, because of its long molecular chain, entangles around the pore spaces and plugs the microsize pores, which eventually reduces the filtration loss volume up to some extent. By observing the synergistic interaction between MWCNTs/TiO2 nanoparticles and PAC, this study develops valuable insights that assist in improving the performance of drilling fluid and minimizes the wellbore instability issues in the oil and gas sector.

Process and pit design for waste water-based mud treatment and drilled cuttings stabilization for cluster of oil wells

Environmental degradation through crude oil and gas exploration has attracted international attention over the past decades. This prompted the development of dewatering and clarification processes to treat the waste water-based mud emanating from drilling activities. There is also the need to carry out proper solidification and inertisation and stabilization process for the drilled solids. It has caused the development of many chemicals to assist solidification and inertisation and stabilization process. The costs of treatment of waste water based mud and drilled solidification and stabilization are high. Economy of proper waste pit design is also necessary to enhance fluid and process control to minimize the cost of operation. This research work is coming out from practical field operation and is used to illustrate how proper process and pit design can enhance effective and economic waste water based mud and drilled solids inertisation and stabilization process in the oil and gas industry.

The integration of dynamic value stream mapping and cost time profile method for optimizing offshore drilling logistic base operations

The research aims to analyze the integration of Dynamic Value Stream Mapping (DVMM) and Cost Time Profile (CT-profile) method for optimizing offshore drilling logistic base operations. The novelty of the research is the implementation of DVMM and CT-profile that implemented in monitoring system INTACTS (Integrated Dynamic value stream mapping and Cost time profile for shore base operation) which is directly connected to shore base material movement recording system. Each successful lift performed in JIT mode will be recorded and its characteristics studied so that it can be applied to other material lifting operations. This research uses data on the lifting operation on July - December 2020. The new method is applied in a logistic system for drilling activity. The research shows that DVSM is suitable to be applied for logistics in off shore base problems since the job and situation are very dynamics.

Physics-driven feature alignment combined with dynamic distribution adaptation for three-cylinder drilling pump cross-speed fault diagnosis

Monitoring the health of drilling pumps and diagnosing faults is crucial for the smooth operation of oil drilling activities. However, existing deep learning algorithms struggle with varying speed conditions. To address this, we propose a method that combines physics-driven feature alignment with Dynamic Distribution Adaptation (DDA) for diagnosing drilling pump faults across varying speeds. Our physics-driven feature alignment method reduces discrepancies between samples by aligning amplitude values, angular sampling frequencies, and impulse phases of signals. DDA further improves cross-domain feature matching by dynamically adjusting marginal and conditional distributions during domain adaptation. Experiments on a three-cylinder drilling pump platform under varying speed conditions demonstrate the superior performance of our method compared to state-of-the-art approaches.

Down-the-hole drilling construction acoustic research

nd The Alaska Department of Transportation and Public Faculties (DOT&amp;PF) is conducting research to characterize underwater sounds from down-the-hole (DTH) drilling activities. This method of drilling is commonly used to drill holes through hard or rock substrates to support piles or tensions anchors for piles. A pneumatic DTH hammer is driven by pressured air coming from an air compressor that provides the energy to power the percussion piston that hits the drill bit with a specific impact frequency and energy to break the rock and advanced the hole. This activity produces continuous and impulsive sounds that affect marine mammals. Pile installation in marine environments typically uses vibratory drivers and/or impact pile driving. Underwater sounds from these activities have been well documented in publications, for example, there are compendiums prepared by Caltrans, and the U.S. Navy, along with many project-specific compliance reports submitted to resource agencies. However, there is limited acoustical data available for DTH activities, as the first published measurements were only made recently. The National Marine Fisheries Services (NMFS) recognizes the acoustical issues with DTH noise and is encouraging the collection and dissemination of additional sound data. This paper describes the research conducted and available DTH acoustic data.

Assessing the application of ultradeep azimuthal electromagnetic resistivity tools in detecting igneous formations ahead of the transmitter

The Faroe–Shetland basin (FSB) is considered challenging for oil and gas exploration due to its complex geological structure and limited exploration drilling activity. The costs of drilling in the basin are the most expensive within the United Kingdom Continental Shelf (UKCS) due to varying geological and engineering challenges. The prevalence of igneous sill complexes within the basin present drilling hazards that contribute to drilling nonproductive time (NPT) and are documented in multiple studies. Recent advancements in ultradeep azimuthal resistivity (UDAR) technology which utilizes the look-ahead portion of the electromagnetic (EM) signal presents an opportunity to assess its suitability as a derisking tool to ‘look-ahead’ and detect igneous intrusions in volcanic basins. This paper utilizes resistivity log data from Well 214/28-1, which encountered multiple igneous intrusions and is used to validate the ability of these tools to detect the intrusions. The EM look-ahead technology detected with good confidence the top of an igneous intrusion 72 ft (22 m) true vertical depth (TVD) ahead of the transmitter and once drilled, detect the base of the intrusion 54 ft (16 m) TVD ahead of transmitter. The detection of the intrusions prior to drilling and information on intrusion thickness can enable proactive drilling decisions to reduce nonproductive time.

Evaluasi Invisible Lost Time dan Non-Productive Time Pada Sumur X Menggunakan Data End Of Well

One of the characteristics of the oil and gas sector, especially drilling activities, is High Cost, namely high operational costs. Therefore, efficient and effective use of time is necessary to reduce operational costs. Evaluation of the influence of ILT and NPT on drilling activities was carried out to find the factors that made drilling time so long. Identifying KPIs for each activity is necessary to find out what activities can be optimized. From the analysis results it was found that the Invisible Lost Time value was 33.12% (198.75 hours) and Non-Productive Time was 18.37% (110.25 hours) caused by less than optimal performance and equipment failure. The author believes that the factors causing the relatively high ILT and NPT can still be optimized so that the costs required during drilling activities are in accordance with the desired planning.

The impact of exploration/appraisal activities on the recovery per well in North Perth Basin

The North Perth Basin (NPB) in Western Australia has experienced significant petroleum industry activity over the past 3 years (2021–2023), marked by the drilling of exploration and appraisal wells by various operators, along with notable merger and acquisition transactions. This flurry of drilling activity, coupled with the acquisition of new seismic data, have enhanced our understanding of the variability within the primary petroleum play levels – namely, the Permian ‘Kingia’ and High Cliff reservoirs. This understanding is crucial for assessing the future potential of domestic gas supply in Western Australia. This paper aims to elucidate how recent drilling efforts have narrowed the basin-wide portfolio of available gas prospects relative to the situation in early 2021, and how the landscape of undiscovered gas resources has evolved. This shift is attributed to both unsuccessful exploration attempts and revised estimates of well deliverability. Furthermore, an updated long-term production forecast for the NPB – considering existing gas pools and the newly assessed undiscovered resources – emphasises the urgent need to re-evaluate the narrative concerning gas availability for the domestic market. The Permian gas plays within the NPB have proven to be more intricate and unpredictable than previously believed. Nonetheless, their significance to the Western Australian economy is anticipated to be substantial for many years ahead.

The importance and evolution of corrosion inhibitors in the drilling fluid for the offshore drilling industry

Abstract The fundamental process of drilling within the oil and gas industry appears straightforward, entailing the creation of a borehole that connects to the underlying oil reservoir. An indispensable component in this operation is the mud formulation, playing a critical role in lubricating the drill bit and facilitating the efficient removal of cuttings. However, a notable challenge arises due to the machinery’s predominantly metal composition, leading to corrosion concerns. Various strategies, including the application of corrosion inhibitors, have been introduced to address and manage this corrosion challenge. This review provides a comprehensive exploration of recent research endeavors focused on corrosion inhibitors in the context of offshore drilling operations. It aims to offer insights into the diverse types of corrosion commonly encountered during drilling activities in marine environments. Moreover, the review delves into an in-depth examination of various corrosion inhibitors utilized for mitigation, shedding light on their performance characteristics and limitations within the specific scope of drilling operations. By scrutinizing these corrosion inhibition strategies, the review contributes to a nuanced understanding of the evolving landscape in drilling technology and the measures taken to ensure the longevity and efficiency of drilling equipment.

Optimizing the impact of rheological properties on bentonite pre-hydrated based drilling mud through the utilization of pre-hydration

In offshore drilling activities, the employment of seawater mud is indispensable, and its adoption is steadily increasing. Traditionally, attapulgite has held a dominant position as the key element in seawater mud composition. However, a shift is underway towards substituting attapulgite with bentonite owing to the manifold advantages that the latter presents. Bentonite boasts favourable viscosity characteristics and efficient control over water loss, outperforming attapulgite particularly in terms of its capacity for clay absorption. Nevertheless, to harness its thickening capabilities for use with seawater, bentonite necessitates a preliminary hydration process. The pre-hydration procedure involves the amalgamation of seawater and bentonite at a low mixing speed for a duration of 10 minutes, succeeded by a resting interval spanning 16 hours. The integration of this pre-hydrated bentonite system necessitated an extensive research undertaking, encompassing a comprehensive review of pertinent literature, the collection of seawater samples, laboratory experiments conducted at three distinct temperatures comparing both fresh water and seawater formulations, the incorporation of diverse additives to augment the assessment of the mud’s physical attributes, meticulous measurement of the drilling mud’s physical properties, implementing treatments to enhance measurement values under heightened temperatures, meticulous analysis of acquired data, and the comprehensive documentation of research findings in scholarly publications. The crux of this research endeavour lies in attaining the objective of incorporating pre-hydrated bentonite as a pivotal constituent within seawaterbased drilling mud. The realization of this goal hinges on the congruence of the measured physical properties of the drilling mud with predefined specifications. Through a rigorous exploration of these methodologies and a systematic approach to research, the study endeavours to foster advancements in seawater-based drilling mud formulations and their operational effectiveness within offshore drilling contexts.

Influence of green chemicals, biopolymers, and nanoparticles on torque and drag forces during drilling activity

Influence of green chemicals, biopolymers, and nanoparticles on torque and drag forces during drilling activity