bluuebunny/crossref_metadata_2025_split huggingface dataset:
A New Experimental Core Analysis Method for Formation Permeability Measurement Under Two-Phase Condition
Authors: Zhang Fengyuan , Zhang Qiang , Zhang Zhengxin , Rui Zhenhua , Liu Yueliang , Zhang Wei , Zheng Xiaojin , Torabi Farshid , Afanasyev Andrey 
Published: April 2023

AbstractExperimental methods for core plug analysis are widely used to measure formation permeability under steady-state flow or unsteady state flow conditions, which provides important geoscience information on formation properties. However, typical laboratory techniques hardly reproduce the two-phase water and hydrocarbon storage and transport conditions that formation is subject to in reality. Accordingly, we presented an integrated experimental core analysis method for permeability measurement, which better reproduces these two-phase conditions.The proposed experimental method consists of two-phase fluid initialization and production test, during which the gas rate, liquid rate, and inlet/outlet pressure of the core plug are recorded simultaneously. After constructing with uniform distribution of gas and liquid, the core sample is transformed into a two-phase production process under the conditions of variable rate and sealed boundary. Rate transient analysis is performed to estimate formation permeability with the gathered two-phase rate decline and pressure data. A two-phase diagnostic plot and specialty plot are introduced to identify flow regimes and extract permeability from the slope of a straight line during the experimental data analysis.In this paper, commercial software is used to generate synthetic data for the production test of a core plug. The simulation of two-phase fluid initialization and production tests were conducted on core plugs. The simulation results show a unit-slope straight line on the generated diagnostic plot, which indicates a clear boundary-dominated flow (BDF) regime. By performing a straight-line analysis, we calculated the permeability of the core plug with the slope of straight-line period on specialty plot. The good match of the calculated permeability with the reference value confirms the accuracy of the proposed experimental method with the relative error less than 10%. In addition, the proposed two-phase core analysis method can enormously accelerate test-time, as the permeability of selected rock sample can be estimated in less than 10 minutes.Instead of measuring permeability only under the condition of single phase flow, this paper presents a laboratory technique that combines the experiment of small-diameter core production test under two-phase flow with rate transient analysis method. Unlike prior experimental techniques, the proposed method reproduces the more realistic condition of two-phase flow in the formation during permeability measurement. The two-phase core analysis method achieves the objective of accurate and fast characterization of formation permeability, which is a more "apples to apples" comparison between the fluid flow in the actual reservoir and the core plug.
Highly Efficient Eco-Friendly Polyurethane Composites with Palm Fibers in Removal and Recovery of Oil Spills
Authors: Paredes Zaldivar Mayté , Pinheiro de Queiroz Guilhermo , Martins Wagner , Mulinari Daniella Regina , Silva Freire Paulo Cesar , de Souza Barbosa William , Vilela de Faria Giancarlo 
Published: April 2023

Abstract
This work aims to reveal the highly efficient performance of eco-friendly polyurethane (PU) composites with natural palm fibers in the removal and recovery of oil spills. In addition, it is shown that this composite allows oil recovery and reuse, and still the composite material reusability. The study was done from the composite material and mini sorption barriers, up to real scale barriers. The eco-friendly polyurethane-natural palm fibers residue composite foams were obtained by the partial replacement of petrochemical monomers with polyols derived from vegetable oils, and the addition of natural palm fiber residues. The initial tests were carried out in the laboratory using the composite material and mini sorption barriers with 0.3 m. The oil sorption capacity and the sorption efficiency in oil and water were studied using crude and used oils. Also, the oil recovery and the material reusability were tested. Additionally, the oil spill sorption and containment performance of real scale barriers, 3 m long, were tested at a swimming pool and at wave bay and river flow scenarios, respectively. The study showed that composite material exhibited higher efficient oil sorption capacity and recovery efficiency in water, reaching values of 20-26 g.g-1 and 85-99 %, respectively. This material still allows the sorption of the dissolved oil, been possible to observe the oily water clarification by the demulsification. Besides, it was possible to recover about 60 % of the oil and material reuse or recycling of at least 7 cycles. Also, efficient results were obtained for the mini sorption barriers. In the case of the bigger barriers, the tests also reveal high oil absorption capacity and that barriers are effective in the adsorption of oil spills. It was observed that the barriers absorbed almost 100% of the oil and maintained its buoyancy. The buoyancy remains greater than 46% after oil sorption. Then, we can conclude that the developed and patented eco-friendly polyurethane - natural palm fibers residue composite foams are excellent materials to be applied in sorption barriers, and these barriers are highly efficient in the removal and recovery of oil spills, also allowing the recovery of oil and the barrier reusability. The novelty is the introduction of efficient eco-friendly composite materials used in sorption barriers. This composite material was tested at the Centre of Documentation, Research, and Experimentation on Accidental Water Pollution (CEDRE), in France, certifying their efficiency and that the material can be recommended for use as a floating sorbent for oil pollution.
Broachment Studies Considering Fracture Propagation in a Well Containment Analysis
Authors: Cutrim Fabio Sawada , Azevedo Cecília Toledo , Baptista Renan Martins , Fernandes André Alonso 
Published: April 2023

Abstract
Well Containment Analysis – WCA - is a set of integrity analysis criteria in a shut in scenario performed during the well design phase. The installation of a capping and shut in of the well shall not induce hydrocarbon leakages to the seabed. One of the integrity analysis criteria within WCA is a situation in which the well, in a blowout scenario, is closed with the capping, and a fracture is then initiated at a specific casing shoe of the well, propagating through shallow formations. The analysis ensures that the time for fracture propagation to reach the mudline is longer than the time to drill a relief well and have the well controlled.
When considering a situation of a fracture propagation in a blowout scenario after capping and controlling the well there are two main possibilities: (I) a shallow reservoir can absorb the hydrocarbon flow from a deeper reservoir, (II) the time required for the fracture propagation to reach the seabed is greater than the time needed to control the well in blowout situation, guaranteeing that there is no fluid broaching to the seabed. When considering the time for fracture propagation, a safety margin is needed due to uncertainties in the geological data.
This work aims to present a few case studies where well projects didn’t attend WCA analysis considering P90 pore pressure scenario and needed further analysis to ensure attendance of well integrity. In this situation, studies were done considering fracture propagation beginning after the well closure due to a hypothetic blowout, trying to analyze if hydrocarbons would broach to the mudline, and if so, how much time such an event could occur.
Study results show the impact of geology and geomechanics on fracture propagation. There are situations in which the fracture remains confined due to the presence of a shallower reservoir and others where the fracture broaches to the mudline in a short amount of time.
This analysis has the potential to turn the concept of well integrity more flexible, allowing the well designer to combine, in a tentative optimal way, a safe and feasible design in more challenging scenarios.
Filtration of Biodegradable Fiber-Containing Drilling Fluids for Offshore Shallow Weak Formations
Authors: Takahashi Kazuma , Naganawa Shigemi , Bjarkason Elvar Karl , Mukai Ryutaro 
Published: April 2023

Abstract
Fiber-containing drilling fluids are expected to improve hole cleaning efficiency and have filtration properties that help to form a strong mud cake on the borehole wall. The objective of this study is to evaluate the filtration properties of drilling fluids containing a novel biodegradable polymer fiber.
The novel 100% bio-based polymer, named PHBH (TM), biodegrades easily in a seawater environment. The filtration properties of drilling fluids containing PHBH fibers were investigated through static filtration tests using an API (LPLT) filter press and a high-temperature and high-pressure (HPHT) filter press. The HPHT tests were conducted at 93°C (200°F). The tested base fluids contained 1.5wt% of bentonite or sepiolite clay, and 0.1 to 0.4wt% of polyanionic cellulose (PAC-HG) as a viscosifier. Sepiolite was considered since it is more thermally stable than bentonite.
From the results of API and HPHT filtration tests, adding 0.4wt% PHBH fibers reduced the amount of filtrate by approximately 5 to 7%, and the thicknesses of mud cake by approximately 24 to 34%. Among the 3, 5, 10, and 14 mm-long fibers tested, 14 mm long fibers resulted in the maximum reductions in filtrate and mud-cake thickness. Analysis of the solid concentration in the suggested that thin and strong mud cakes might form by adding the PHBH fibers for both bentonite- and sepiolite-based fluids.
Compared to the existing commercial fiber additives, the novelty of application of the new biodegradable fiber-containing drilling fluids to prevention of lost circulation or borehole wall strengthening in offshore shallow weak formations is highly environmentally-friendly for sustainable oil and gas developments. The biodegradable fiber-containing fluids can be applied in various uses like completion fluid, cementing spacer, etc.
The Challenges of Executing Pull in and Pull-Out Operations With ROV in Scenarios Designed For Shallow Divers Intervention
Authors: Santana Andre Bevilaqua Luiz Bevilaqua , Correa Ygor Fernandes Dos Santos Manhães , Da Silva João Luis Batista , De Oliveira Allan Carré Carre , Marino Lucas dos Anjos Cristino , Junior Roberto Alves de Lima , Giacomin Joelis Herminio , Barbosa Raquel Vila , Chargue Luciana Sa Silva Guillamet 
Published: April 2023

AbstractOver the last few years, Petrobras has sought to reduce divers’ exposure to risk, as well as reduce this dependence on human diving in its underwater activities and reducing critical resources that impact underwater interconnections.A subsequent de-risking phase of the principal technological gaps and critical engineering activities were structured to support a robust solution to be installed and validated in a full-scale prototype tool. All feasibility studies indicated the need development of tools that can be less impacted by the relative movements between floating platforms and ROVs (Remotely Operated Vehicle) in shallow water operations, allowing bellmouth preparation operations, for example.This paper presents the challenges that Petrobras has been facing to perform the pull in and pull out of flexible pipes with ROV in scenarios made to operate with divers.
Through-Life Modelling of Rock Berm-Pipe-Seabed Interactions
Authors: Borges Rodriguez Antonio Alberto , Gaunt Peter Francis 
Published: April 2023

Abstract
This paper portrays salient features of the rock-berm pipe seabed interaction affecting the through-life axial restraint of rock berms installed intermittently over High Temperature High Pressure (HTHP) pipelines including: (i) axial displacement cycles of a pipeline leading to cyclic compaction of the soil and associated to this, downwards movement of the pipe and unloading of the rock berm-pipe contact. This is followed by a gradual re-gain in the system axial restraint by the process of (ii) cyclic soil hardening, and (iii) the process of ‘arch’ collapse promoted by the axially moving pipeline.
Earlier numerical studies (in Carneiro et al., 2017, Borges-Rodriguez et al., 2018) demonstrated unloading of the rock berm-pipe contact by ‘arching’ of the stresses in the rock berm as the pipe penetrates the seafloor. Observations of unloading of the rock berm-pipe contact and subsequently, of the axial load re-gain due to pipe movements, have been made in a suite of centrifuge physical model tests (in O'Beirne et al., 2022a, b). An analytical tool has been developed to capture these effects and is presented here.
More specifically, the model describes the evolution, in a cycle-by-cycle manner, of the axial restraint by the rock berm-pipe-seabed system, allowing the tracking of the axial restraint of the combined system across the operational life. Features of the analytical tool include the prediction of soil volume compaction and downwards displacement of the pipe with cycles, and of an initial and significant ‘drop-off’ in the axial resistance associated with the pipe penetration. The analytical model also reproduces the re-gain in system axial resistance that develops through the combined effects of soil hardening through the process of episodic shearing and re-consolidation, and by the pipe axial movements disrupting the force ‘arches’ set-up along the berm. The analytical tool has been calibrated through dedicated numerical analysis and the results of model tests in the public domain. The tool permits analysis of a range of pipe and soil properties and rock berm geometries and seabed materials. The tool's modelling of the arching phenomenon and post-arching recovery in axial resistance is through a sound theoretical framework. Hence, the analytical tool provides a robust basis for screening the concept of rock berm installation to manage pipeline axial end-expansion, buckle-to-buckle feed-in and arresting the walking propensity. Finally, and based on the demand for axial restraint, the tool can be used for form-finding of the berm for the accurate evaluation of rock volume requirements.
Application of Machine Learning Model for Estimating the Geomechanical Rock Properties Using Conventional Well Logging Data
Authors: Gabry Mohamed Adel , Ali Amr Gharieb , Elsawy Mohamed Salah 
Published: April 2023

Abstract
Building a geomechanical model for reservoir rocks is crucial for oil and gas operations. It is essential to solving multiple designs like wellbore stability for drilling operations, hydraulic fracturing, and sand production prediction for production operations. The best method to build a geomechanical model is to measure in the lab or calculate it from the dipole sonic log. However, it cannot be practically done routinely due to the high cost of logging and processing the dipole sonic logs.
With the training of a machine learning model using conventional logging data and dipole sonic logs and static geomechanical measurements in the lab, a machine learning tool is provided to predict the dipole sonic logs and build a geomechanical model using routinely recorded well logs like gamma-ray, resistivity, neutron porosity, and density. The calculated minimum horizontal stress was calibrated practically with the derived closure pressure derived from several diagnostic fracture injection tests.
This paper provides a practical implementation of a theory-controlled data learning model. It introduces an innovative way to build a calibrated machine learning tool that can predict shear and compressional wave velocities and estimate the rock mechanical properties using the regular conventional well logging data, which are helpful for oil and gas operations.
Methanol + Hydrogen - A Prospective Alternate Fuel for Cleaner Offshore Power Generation
Authors: Narayana Iyer Subramanian , Megaritis Thanos , Ganippa Lionel , Krishnamoorthy Harish Sarma 
Published: April 2023

Abstract
This paper analyzes the benefits of employing reciprocating engines to power offshore oil and gas (O&G) loads using methanol as fuel instead of (or mixing with) diesel that has been used conventionally. The study is carried out on a methanol-based single-cylinder, 50-liter, heavy-duty reciprocating engine for two test cases of power (30 kW and 111 kW) at different boost pressure and injection timing. In this investigation, 1-dimensional modeling and analysis using Ricardo Wave software was performed. Then, the effect of adding small amounts (&lt;10%) of hydrogen into the engine in terms of performance improvement and emissions’ reduction is explored. Moreover, engine performance, indicated thermal efficiency, and CO/NOx emissions are compared for different boost pressure values at varied injection timing and constant power. The tests are carried out by modeling multiple use cases and comparing them, including (i) direct injection of methanol, and (ii) direct injection of methanol with port injection of hydrogen by spark ignition method. The addition of hydrogen with methanol results in a significant reduction in emissions and increase in the indicated thermal efficiency. Moreover, advancing the injection timing and increasing the boost pressure decrease the CO/NOx emissions, and also improve the indicated thermal efficiency. This paper presents these analyses in detail for multiple test conditions.
Wellbore Casing Integrity Envelope for Deepwater Reservoirs – Workflow and Case Study
Authors: Gandomkar Arjang , Pei Jianyong , Tjengdrawira Marius 
Published: April 2023

Abstract
It has been known that offshore wellbores are prone to experience large deformation due to compaction of the reservoirs during the field production life. The induced compaction results in undesired effects on wellbore integrity and reservoir performance. Wellbore diameter restriction, casing shear, and cement de-bonding are a few examples of such effects. Permeability/porosity losses and fault reactivation are major concerns for the reservoir performance. It is the utmost goal for any operators to ensure long-term safety and integrity of their fields and wellbores for economical and HSE purposes. This demands a complex planning and modeling that a classical 1D geomechanical workflow cannot provide. Complex numerical simulation workflows coupled with adequate engineering planning and design are required to estimate safe operational characteristics given a field and wellbore conditions. Operators can characterize the safe operational envelope in terms of depletion and drawdown pressures since the reservoir compaction is highly dependent on these parameters.
Several operators such as ExxonMobil have established their casing integrity evaluation throughout the lives of their fields either with analytical solutions, decoupled modeling by separating rock model from the casing behavior, or a sophisticated two-scale 3D finite element model (FEM) [3, 6]. It is believed that that the latter approach offers more in-depth understanding of the loading that may compromise casing integrity during production. This paper illustrates the necessary modeling components and workflow that is required to predict the safe depletion and drawdown pressure without compromising the integrity of a casing and re-activating any faults or fractures. ABAQUS 3D FE geomechanical modeling was coupled with the result of reservoir simulation to study drawdown and depletion effects. An FE submodeling technique was applied to account for formation, casing, and cement interactions. The technique will allow a fully coupled analysis using the boundary conditions established by the global (field-wide) 3D FE modeling. Any types of casing deformation modes (shear, tensile, buckling, and collapse) under in-situ stress changes due to depletion and drawdown, rock mechanical and fluid behaviors, and wellbore trajectory can be evaluated.
In this paper, a deviated deepwater wellbore is analyzed using the Casing Integrity Envelope workflow. Two sections of a wellbore prone to casing deformations, one above and the other inside the reservoir, are examined. The resulting drawdown and depletion envelope enabled the operator to plan actions to mitigate well failures and to ensure safe operations. In general, the developed workflow can be created for any field, casing/cement configurations, and environment. It incorporates coupling of various materials with complex boundaries which are the main advantages over the traditional analytical models.
Impact of Reservoir Salinity on Oil Recovery Using Surface-Modified Silica Nanofluid for Offshore Oilfield Applications
Authors: Kumar Ravi Shankar , Arif Muhammad , Kumar Sikandar , Sharma Tushar 
Published: April 2023

Abstract
Hydrocarbons (oil and gas) contribute significantly to the total global energy requirement, thus, oil recovery improvement from the current reservoirs is key. Nanotechnology based enhanced oil recovery (EOR) is a potential technique that can considerably improve the oil recovery factor. However, complex reservoir fluids which are highly saline (specifically in offshore) affect the stability of nanofluids and limit their efficacy through pore blockage during flow through porous media and offer a reduction in oil recoveries. This study thus proposes a novel technique for nanofluid formulation using different additives and surface-active agents and investigated them for stability in different techniques. Moreover, the formulated nanofluid is then tested for EOR in sand-pack experiments. The sand-pack is fully saturated using a NaCl solution; providing a realistic high saline laboratory model during flooding similar to an offshore environment. Various studies involving the stability and viscosity of nanofluids, and efficiency for EOR for offshore reservoirs have been reported. The efficiency of the nanofluid systems for stability, rheologicalproperties, and EOR has also been compared with the conventional nanofluid and newly formulated nanofluid flood schemes. This study reports that the saline environment severely damage the nanofluid stability by reducing electrostatic repulsive forces (screening electrical charges of NPs), subsequently, quick settlement of NPs was observed. The agglomeration and sedimentation of NPs within the nanofluids generally reduces the cumulative oil production by permeability impairment. However, the inclusion of surface active agents (surfactant) re-establishes the physical stability of the surface coating mechanism which curtailed the effect of salinity, especially in offshore oilfields. The surface-coated NPs in the nanofluid enhanced stability for a prolonged duration by maintaining nanometer size which is crucial to avoid early particle aggregation thus demonstrating incremental oil recovery in offshore oilfield applications. This study discusses the novel fabrication methodology of stable nanofluids using colloidal aspects for offshore oilfield applications where formations salinity becomes a major challenge during flow through porous and permeable media.