bluuebunny/crossref_metadata_2025_split huggingface dataset:
Drilling Performance Improvement in Mature Field with Limited Investment Period by Implementing Novel Technology Application
Authors: Pratama Raka Cahya , Hutabarat Teddy , Fitryansyah SM Yudy , Benny Benny , Dova Rudi 
Published: October 2019

Abstract
Horizontal well type was selected to optimize drainage of a mature field which had less than 3 years prior concession end. However, the well construction of horizontal well is relatively more challenging compare to other well type which will lead to higher cost. Offset well execution data showing that the challenges of drilling this well type were wellbore instability, drill bit worn out due to gravel zone, uncertainty on marker prognosis and the potential differential sticking on lateral section (inside the depleted reservoir) especially during running pre-perforated liner as completion equipment. It was realized that drilling performance improvement is required to reduce the cost and accelerate the production.
To overcome the challenges, several technologies were introduced. Drilling fluid optimally designed to support borehole stability and real-time adjustment were performed by analyzing the drill cutting. Ridged shape cutter bit utilized to aid during penetrating the gravel zone. To maximize the penetration rate, point-the-bit Rotary Steerable System was utilized for better weight transfer and improved wellbore geometry compare to conventional mud motor system. To manage uncertainty of marker prognosis, the Bottom Hole Assembly (BHA) was designed to achieve maximum dog leg severity capability by minimizing the number of stabilizers. Near bit gamma ray sensor also installed to aid timely formation marker identification. To mitigate risk of differential sticking, the bridging agent sized to fit with the formation permeability through particle size distribution analysis. Centralizers also installed on pre-perforated liner assembly to minimize contact area which might cause differential sticking.
Though these technologies application has been used on many occasions, they were new to this field development which raised concern over their potential risk, especially with limited investment period. Therefore, a series of execution assurance processes were performed. Cross-functional risk assessment sessions were held to review trade-offs of each new technology potential value with the potential cost incurred by considering the possibility of success and potential changes on other aspect of the well construction that need to be adjusted to accommodate the application and mitigate its potential risk. Then a drill-well-on-paper session held with all personnel that would involve by simulating the drilling execution following the procedure which then improved by creating mitigation steps or provide clarity. Artificial intelligence assisted decision support center was also utilized to monitor execution and aid performance improvement recommendation utilizing geomechanics, hydraulic, torque and drag model as well as the field best practices.
These all result to 17% cycle time improvement with 9% lower cost compare to typical well. The production sweet-spot zone exposure also increased by 20%.
Storage Tank Emergency Preparedness in a Modern Era: Incorporating Technology Advancement on a Mature Facility
Authors: Kristanto Kristanto , Witono Johanes-Anton , Victor Irwan , Garmana Iqbal-Aprian , Wongso Henkie-Hartono , Situmorang Ade , Hariyanto Geoffrey , Kusmawan Herdy , Pebtiadi Teguh , Nurdin Farid , Rosyadin Gunawan 
Published: October 2019

Abstract
Mature facilities were previously built based on outdated code and standards which do not yet incorporate lessons from recent incidents. In order to have more robust plant safety management, plant design and Emergency Preparedness are upgraded incorporating new technologies.
The selected upgrading methodology involves comparing the available emergency scenarios versus all possible emergency scenarios that might happen to the facility. Scenarios that already have appropriate mitigations are reviewed in order to adapt with the latest plan condition. Meanwhile, scenarios that were yet considered in the initial design are carefully assessed. New available technologies are identified and selected to mitigate this new identified scenario. Upon the completion of necessary modifications, facility emergency response procedures are updated comprehensively
Triggered by full surface tank fire incident in one of refinery, detail gap analysis was performed to check the potential emergency scenario and its available mitigation at Senipah Terminal. Based on gap analysis, it was confirmed that initial design of this &gt; 40 year storage tank Facility was not designed to cope with full surface fire but it was designed to mitigate rim seal fire. Based on thorough study, following are improvement of safety and operation aspect of storage tank which already been implemented including: provision of High Capacity Cannon Monitor (HCCM) complete with fire network and foam system improvement, on-line tank surveillance and monitoring system installation, rim gap minimizing and fire embark system improvement to improve existing rim seal firefighting system, spill containment system improvement, foam truck replacement to support firefighting scenario. Site emergency contingency plan was also updated to align with the latest modifications.
Throughout plant lifetime, the emergency preparedness document is live document which should be continuously updated refering to the most recent standard and lesson learnt from the industry. Emergency preparedness is also much linked to the plant design. Any modification on the facility shall be followed by reviewing and updating existing plant emergency management system.
Challenges of the Fluid Modeling and Initialization of a Non-Equilibrium Oil Reservoir: Case Study for Field S in Malaysia
Authors: Hajizadeh Mobaraki Alireza , AL Mudaliar Kokulananda , Salleh Nor Hajjar , Deo Tewari Raj 
Published: October 2019

Abstract
Compositional grading resulting from the gravity segregation in thick reservoirs is a common phenomenon observed especially in volatile oil or gas condensate reservoirs. Same phenomenon is repeatedly encountered for reservoirs with high temperature gradients. It is also not uncommon if compartmentalized reservoirs indicate areal variations in fluid properties. But drastic variation in composition and fluid properties both vertically and laterally in thin to moderate reservoirs where the reservoir seems to be connected based on initial pressure data may denote non-equilibrium conditions. In this study such conditions will be assessed for a Malay basin saturated oil reservoir and the challenges and proposed solutions are presented.
The individual available samples from appraisal and early production system (EPS) development wells covering six stacked sands each comprising of four segments are thoroughly analyzed for quality and reliability. The information from fluid samples including finger prints for hydrocarbons and CO2, is integrated with pressure and full PVT data to characterize the fluid in this field. Reconciliation of PVT and well test data was harnessed to achieve to a set of representative samples for each reservoir/segment while considering reasonable compositional grading and rate of bubble point depression. The samples were then scrutinized for reliable experimental data.
Various alternatives of non-equilibrium initialization vs. defining multiple equilibrium regions with compositional grading were considered. The pros and cons of each method is discussed in this paper and general hints for selecting appropriate approach is given based on type of reservoir being modeled, the purpose of study and available data. It is shown that a fit-for-purpose approach can be adopted to fulfill the requirements of the FDP while trying to reproduce the reservoir behavior. The role of reservoir management and updating the model regularly as per future performance is emphasized.
The non-equilibrium reservoir systems have not been extensively discussed in the industry and limited case studies and corresponding challenges and solutions have been presented. This paper discusses fundamental phenomena encountered in dealing with such systems and presents solutions based on the nature of the problem and project objectives both in theoretical and practical sense and in this regard it is novel.
Validation of Wax Deposition Models Using Field Data of Western Onshore, India
Authors: Agarwal Jatin R. , Dhingra Simran , Shah Neel , Shah Subhash N. 
Published: October 2019

Abstract
Crude oil samples were collected from three-buried gathering lines of Cambay Basin and were characterized in Drilling Cementation and Stimulation (DCS) Research Center, PDPU for their hydrodynamic (Viscosity, Density) and thermal (Specific heat, thermal conductivity) properties along with solubility curve (WAT, pour point and precipitation curve) at Gujarat Energy Research Management Institute (GERMI), PDPU. Theoretical wax mass fluxes for four available wax deposition models were computed using the characterized properties of crude oil samples. Field wax mass fluxes were computed based on field data obtained from the gathering lines and were compared with the theoretical wax mass fluxes. The field data for both 2 km and 5 km long 8 inch ID gathering lines indicated that the crude oil in these pipelines was flowing under laminar flow regime, while for 25km 8 inch ID gathering line it indicated a turbulent flow condition. This leads us to conclude that the presumption of only turbulent flow condition prevails is a myth; both laminar and turbulent flow conditions can occur. Furthermore, a wax mass flux analysis revealed that field wax mass fluxes for gathering lines with laminar flow regime (Re = 200 to 2300) is in good agreement with Film Mass Transfer (FMT) model, while the predictions from Equilibrium Model (EM) and Matzain models are in good agreement with the field data of gathering line with turbulent flow condition (Re = 5400). These agreements are because, for laminar flow case Chilton-Colburn analogy (no-precipitation case) is satisfied which means no precipitation occurs in the mass transfer boundary layer and large amount of wax is deposited radially in the pipe. While, for turbulent flow conditions, the concentration profile is dependent on temperature profile and complete precipitation or instantaneous precipitation occurs in the mass transfer boundary layer. In our study, we made every attempt to obtain reliable field data for comparison with the existing models. The four unique field cases presented here would be useful to researchers in validating their models. In addition, it made us realize that wax deposition is not only an offshore flow assurance problem but also a major flow assurance problem for onshore operations.
Tight Carbonate Reservoir Characterization and Perforation Optimization Using Magnetic Resonance in Horizontal Well
Authors: Nugroho Cahyo , Fahmy Mahmoud Fawzy , Ray Dipak Singha , Zekraoui Mohamed , Qutainah Riyad , Ghioca Monica 
Published: October 2019

Abstract
The presented reservoir in this paper is a tight carbonate reservoir with vertical and horizontal heterogeneous properties. In particular, the low clay content in this reservoir gives low gamma ray counts, making difficult the layer identification. In addition, the high-resistivity response of hydrocarbon-bearing pay-zones and of the tight layers make more difficult the identification of the reservoir sweet spots. Slim-hole magnetic resonance (MR) logging was deployed in wash-down mode for identifying reservoir sweet-spots for providing lithology-independent porosity and formation fluid characterization.
The well placement over a deep elongated anticline with steep dips and the lowering of the production liner are challenging. Consequently, the field is being developed using horizontal wells that cut across multiple reservoir layers to maximize reservoir contact and drainage.
MR was acquired with dual wait time enabled T2 polarization to differentiate between moveable water and hydrocarbons. After acquisition, the standard deliverables are partial porosities and permeability index. The porosity is divided into clay-bound water (CBW), bulk-volume irreducible (BVI) and bulk-volume moveable (BVM). The effective porosity, the permeability index and the permeability-effective porosity ratio were used to evaluate the rock quality. The classification was based on the gradient of the permeability-effective porosity ratio, where a steeper gradient is interpreted as high flow zone, a gentle gradient as low flow zone and a flat gradient is considered as tight baffle zone.
Based on the MR flow units and fluid types (CBW, BVI and BVM), the drilled interval was classified into six compartments of high flow, one compartment of low flow and five tight baffle zones. Accordingly, the perforation plan was optimized to fit the high flow units only. Comparing to the conventional log analysis, MR excluded approximately 700 ft of non-productive reservoirs, leading to more than 250,000 USD cost savings in perforation, drilling time and production optimization.
The well was drilled with a distance-to-bed boundary tool; however, enormous potential exists to use this slim MR tool as a non-radioactive sourceless solution for geosteering through reservoir sweet spots while delivering wells that are more productive safely.
The Influence of Nano-Silicon Material on Clay Swelling Effect
Authors: Rong Xufeng , Wang Yanling , Forson Kobina , Guo Baoyu , Liu Junyi , Wei Mingzhen 
Published: October 2019

Abstract
In traditional production environments, clay expansion in the near wellbore area may hinder drilling and completion operations. However, most of the above stabilizers cannot meet the actual requirement because the general clay stabilizer cannot migrate through small voids, and can also cause damage to the environment and be very expensive. Herein the behavior of nanoparticles in stabilizing clay particles and the condition for reducing the clay swelling and reservoir damage are investigated.
The adsorption characteristics of nanoparticles on the core surface were studied by adsorption experiments and SEM. Displacement experiments of cores was conducted to discuss the migration behavior of nanoparticle inhibitors. In addition, the Malvern Zetasizer light reflectometer was employed to measure the electrokinetic potential of nanoparticles. To obtain a nanoparticle dispersion system, the dynamic dispersion measurement information of nanoparticle size distribution was collected. In the stability, by controlling the temperature, pH, pressure and other factors, the effects of these factors on the stability of the clay are investigated to obtain the mechanism of action of the nanoparticles.
The core piece was immersed in 1g/L nano-liquid. After adsorption for a period of time, it was observed by SEM that the hydrophobic nanoparticles could form an adsorption layer on the core surface and show a strong hydrophobicity. The nano-electromotive potential is stable at +38.2mV and −36.0mV, indicating that the dispersion is very stable. The dynamic dispersion measurement surface size of nanoparticle dispersion is much smaller than the typical pore and pore channel size in most reservoirs. The microparticles are dispersed and injected through a filter device with a pore size of 200 nm and all of them are dispersed through the core. There is no residue in the filter device, thereby achieving effective migration in the core. It can be concluded that the adsorption effect is stronger under alkaline conditions when the adsorption amount is only reduced by 10% at 950 °C. This is not affected by the pressure factor and also the adsorption effect is stable.
The action of mechanism between nano-silicone material and clay is obtained, and different factors are investigated to find out the prospect of nanoparticles in improving clay stability and reducing the reservoir damage.
Infill Wells Placement in High Water-Cut Mature Carbonate Field with Simulation Opportunity Index Method
Authors: Bernadi Bondan , Silalahi Eli Saut , Reksahutama Agun , Miraza Donny 
Published: October 2019

Abstract
Despite intelligent method such as numerical simulation model has been used, identifying areas or zones that still holding high potential of production still becomes the most challenging aspect in the development of mature carbonate oil field with high water-cut; especially coupled with the lack of required important data to generate such appropriate model. A practical method to explore the sweet-spot areas within the field is then introduced, hereinafter called "Simulation Opportunity Index" (SOI) based on techniques already established in the industry.
SOI is an integration of three (3) independent components whereas each of them is normalized to produce indexes that represent reservoir-permeability thickness, movable oil and reservoir pressure from a historically-matched dynamic model. The method utilizes the historically-matched simulation model in which the water saturation from the dynamic model is calibrated with the recent acquired cased-hole logging saturation log to improve the confidence level. The cased-hole logging saturation log results are treated as the only ground truth of the current saturation within the reservoir thus it plays important role to reduce the model uncertainty and to simplify the workflow in efficiently short time. The SOI method is hence used as an invaluable tool to spot areas for further development such as infill wells. The workflow to produce the potential areas within the reservoirs is discussed in this paper including comparison to see infill wells performance by using both conventional and SOI approaches.
Notwithstanding lesser producible oil reserves due to denser-placed infill wells over time and high water-cut of the field &gt;95%, the method after implementation in numerical simulation is capable to screen-out a number of sweet-spot areas for infill wells placement in the largest mature oil field of RH PetroGas (Basin) Ltd concession in Salawati basin, onshore West Papua, which can be ranked thereupon for execution after sensitivities and economics analysis. The infill wells are still the most technically-favourable development scheme to hold oil production decline about 6%/year in the field. Thus, it is essential to place the infill wells within the most optimum locations that would yield maximum sweep efficiency, acceleration of the expected recovery or incremental increase of the Estimated Ultimate Recovery (EUR) from such heterogeneous reservoirs.
The application of SOI methodology in numerical model is helpful to practically identify areas or zones with high oil potential due to non-uniformity volumetric sweeping efficiency in carbonate reservoirs in relation to their tremendous heterogeneity, variable wettability and dual pore network.
Real-Time Production Logs Surveillance: Automated Workflow Technology Allows Synthetic Sensing of Oilfield Downhole Production
Authors: Bawazir Mustafa , Dallag Mohammed , Shukla Sourabh 
Published: October 2019

Abstract
One goal for oil fields of the future is acquiring continuous and on-demand data as required for field and reservoir management. Synthetic time-lapse production methods are becoming a way of providing this information at and away from wells. Time-lapse production log data acquired over oil fields is used to monitor water sweep in the reservoir. Production logs provide a direct measure of the fluid flowing downhole and detect the unwanted fluid entries. In field applications, this advanced scanning of fluid profiling successfully derisked several infill well locations and identified new workover candidates and drilling opportunities in the fields.
Synthetic time-lapse production logging is a useful complement to understanding reservoir heterogeneity and complexity through tailored synthetic and real data integration. A computer-based workflow has been developed to automate the downhole production flow profile. Production performance of the well is assessed, considering the dynamic time-lapse logging data. A synthetic flow profile is constructed to show the change in water production signature, and the well is further examined if it undergoes remedial actions. Reservoir characterization is a continuous process during the life of the oil field. As new data are available, the model is updated and contains more details. The incorporation of all data allows increased accuracy and reduced uncertainty in characterizing the reservoir.
The proposed methodology requires the acquisition of dynamic production logging data to establish a solid workflow and validate the model. Uncertainty can be eliminated with the acquisition of additional production logs. Recommendations for improvement of the current well condition can be made to reduce the well water cut and improve oil production from the well. Consequently, well classification and candidate selection for workover can be achieved. The results of this work demonstrate the strength of applying multidisciplinary team efforts to develop automated workflows that are relevant to reservoir and production engineers who deal with complex reservoirs with numerous wells.
Reservoir Fluid Sample Decontamination: Application Example
Authors: Altowilib Ali R. , Sequeira Daryl S. , AlOtaibi Fawaz M. , Sahl Ahmed M. 
Published: October 2019

Abstract
An acquisition of representative reservoir fluid samples is important for reservoir management and development. During overbalanced drilling, the high hydrostatic pressure causes mud filtrate invasion into the reservoir. This makes the process of acquiring representative reservoir fluid samples challenging due to the miscibility of Oil-Based Mud (OBM) filtrate with the reservoir fluid. The presence of OBM filtrate impacts the characterization of the reservoir fluid, resulting in inaccurate and not representative PVT laboratory measurements. PVT data generated out of contaminated samples should be avoided as they have the potential of harming field development plans.
In this study, OBM level in contaminated samples was quantified and their compositions were restored through skimming and subtraction techniques. Consequently, the key fluid properties of the decontaminated fluid were successfully predicted through an Equation of State (EOS) software.
The results demonstrated the impact of OBM filtrate on bubble point pressure and heavy-end properties, as concluded by the EOS modelling software, which compared the phase behavior properties of the contaminated and decontaminated fluids. Subsequently, modeled properties like Formation Volume Factor (Bo), Gas-Oil Ratio (GOR), API gravity, and mixture density were all compared to the measured fluid properties of clean fluids. Additionally, the capability and robustness of each decontamination methods were confirmed against the measured original clean composition.