bluuebunny/crossref_metadata_2025_split huggingface dataset:
Steel Tube Flying Lead Accumulated Plastic Strain Calculation
Authors: Bansal Amandeep , Batrony Mimi , Prakash Sunil , Anand Vikash 
Published: November 2020

Abstract
This paper documents a study to determine the accumulated plastic strain (APS) developed in steel tube flying leads (STFLs) assembled in loose-tube bundle configurations throughout their product lifecycle. This lifecycle consists of the various processes involved in the manufacturing of STFLs,including initial tube manufacturing, load-out after tube manufacturing, subsequent shipping, potential over-sheathing, delivery and unspooling for flying lead manufacturing, pressure testing, and the flying lead final load-out. Throughout the product lifecycle, the steel tube undergoes the repetitive processoperations of coiling, uncoiling, straightening, and pressurizing. These operations cause plastic strains to be developed in the tube, which means that the tube experienceshardening,and its mechanical properties are modified throughout its lifecycle. Therefore, it is necessary to account for this accumulation of plastic strain and to ensure that the total APS at the end of the lifecycle is below APS acceptance criteria.
A kinematic hardening material model was used to simulate the nonlinear material behavior. The APS in super duplex tubing within loose STFLs for any number of bend cycles was calculated. The total strain developed in the tubing was calculated on outer fibers in a wrapped configuration. With the total strain (ε) known, the corresponding true stress (σ) can be determined using the tubing material’s true stress-true strain curve. The elastic strain is calculated by dividing the true stress by the tube’s elastic modulus (E). The plastic strain can then be calculated by subtracting the elastic strain from the total strain. Accumulation of plastic strain due to tubing bent about a radius and applied with internal pressure was difficult to obtain, as there were no analytical equations available to calculate it. To approximate the plastic strain developed due to pressure applied, a finite element analysis (FEA) study was completedfor plastic strain variation with respect to different bend radii. Results of the APS calculation were verified with the FEA results for each of the product lifecycle processes. Using this kinematic material model, the difference between the FEA and the APS calculation was within 3.5%.
Drilling, Geo-Steering and Reservoir Characterization Solution in Deep Carbonate Laterals
Authors: Al Muqarshi Moosa Masoud , Beche Amina , Vasquez Bautista Ramiro Oswaldo , Ovezov Murad , Delavari Kamran , Noor Marghub Nabi 
Published: November 2020

Abstract
In a heterogeneous and fractured carbonate hard rock with UCS more than 15K psi, drilling a highly deviated well is a challenging process that would require real time monitoring, using best in class MWD and LWD technology. A client in South Oman is in a development phase of drilling 1000m lateral wells to maximize the exposure for optimum oil production.
The carbonate formation is characterized as heterogeneous vuggy dolomites with a network of regional fractures acting as the secondary source of porosity. The thin reservoir is isolated by thick layer or Anhydrites above and Shale formation below & managing geological uncertainties in real time is going to be the differentiator between success and failure. A combination of hybrid RSS to manage aggressive steering requirements along with distance to boundary imaging LWD tool to identify the bed boundaries & keep the well on course along with an azimuthal resistivity ultra-high imaging for reservoir characterization were deployed to overcome these challenges.
The proposed solution was put into challenge on well X for drilling 5.87in lateral section and 1000 m lateral was successfully drilled. Hybrid RSS with aggressive bend setting helped in geo-steering the well and managed to achieve directional objectives to chase the geological uncertainties. After confirming the formation dip the well was steered 6to 7ft from the bottom conductive layer with the help of distance to boundary resistivity imaging tool. Real-Time High-Definitionazimuthalresistivity images helped in petrophysical interpretation and formation evaluation. Later, better density memory imaging data helped in evaluation of full borehole structural features and detailed fracture characterization. Hybrid rotary steerable systems along with best in class LWD tools provide purpose to fit solution to drill and geo-steered well in the optimum place. Success of this combination has eliminated the risk of exiting the reservoir leading to costly sidetrack scenario. At the same time, it has also helped the client to optimize production by geo-steering the well in the high porosity sweet spot and by Identifying regional fractures.
Developing deep, hard and heterogeneous carbonate reservoirs is a complex and challenging affair and a conventional approach to overcome these challenges is not always producing the best results. A novel approach with the help of advanced rotary steerable and logging while drilling tools helped client in developing the field by minimizing the risks and maximizing the best reservoir exposure characterized, as the well are drilled.
Machine-Learning Guided Fracture Density Seismic Inversion : A New Approach in Fractured Basement Characterisation
Authors: Shamsuddin Annur Asma , Purnomo Eko Widi , Ghosh Deva Prasad 
Published: November 2020

Abstract
The main objective of this study is to map potential fracture density based on a new integrated study of a fractured basement area. A machine learning algorithm of well log fracture density - borehole image log (BHI) guided seismic inversion was performed. Structural seismic attributes which are including maximum and minimum curvature, coherence, ant tracking, neural network, and principal component analysis were used to validate this potential fracture density map. All fractures were interpreted after image from BHI was processed. These fractures were quantified as fracture density log (FDL) based on weight density fractures per meter. The inversion was performed based on the enhanced of Extended Elastic Impedance (EEI) with the FDL. It was done by defining the training data set relating the FDL and its associate EEI. The resolution of inversion is increased by conducting stochastic inversion to generate high frequency relative EEI. The absolute value EEI was obtained by adding the relative EEI with a low frequency model derived from the FDL. A study was conducted in the Field A of the Malay Basin, which is located in transtensional tectonic regimes with the domination of various rock types ranges from metasedimentary rocks to volcanic and igneous rock. The integrated study has been implemented to invert the potential fracture density of the fractured basement area. Based on the BHI analysis, the highest fracture density is defined as 1.3 fractures per meter. Inversion at the well location shows a high correlation and small error of the reconstructed fracture density (FDL). The analysis of cross section and the horizontal slice of inverted fracture density displays good fit with a fracture sensitive analysis, which is structural seismic attributes such as minimum and maximum curvature, coherence, ant tracking, principal component analysis, and neural network. This study provides a better fracture understanding as the resulted inverted fracture density is quantitative. It allows potential fracture density mapping by using geobody analysis through classification or cut off value. The novelty of the study is presented based on the potential to generate a 3D volume of well log calibrated fracture density by empowering the seismic elastic inversion with a sophisticated machine learning algorithm.
Planning for Success: Geomatics in Development Concept Select Phase
Authors: Endot Ernyza , Sim Peter , Ismail Suharti 
Published: November 2020

Abstract
Concept Select (Pre-FEED) is one of the critical and distinct phases in Upstream development projects. Concept Select phase comes before the finalisation of Field Development Plan (FDP). Objectives in this phase includes refreshing the value drivers and opportunity statement, refocus from identifying options to selecting concepts, identifying risks, maturing different operational philosophies in each technical area and for the integrated project, agree criteria on which decisions are to be made and develop tools to help the team focus on decisions (e.g., strategy table). All the objectives above are to narrow down the most possible concepts to be taken into considerations to produce oil and gas.
For a new offshore field development, key disciplines which was involved in the Concept Select phase are Subsurface, Wells, Front-End Engineering and Flowline/Pipelines Engineering. These disciplines will work together in order to deliver the best design which can yield the most optimized options which emphasise the safest and cost efficent with the target of fastest first oil/gas date for maximizing production.
Figure 1 shows a typical upstream project lifecycle. The first phase is after exploration discovery (or field acquisition), major issues are identified in an opportunity framing workshop. All the scenarios and issues are being brought in for evaluations. When downsizing concepts as portrayed in Gate 1, detail to few concepts are being made available. Hazard assessment are being performed and captured in a register which overlying major accidents and events in risk management. These two-phase shown in red box below are the Concept Select phase. The chosen concepts for the project are then being technically and economically evaluated in the Feasibility phase where the risks are being managed qualitatively. After that, comes the detail design and operations of the projects.
Harnessing Power of Technology for Flawless Execution of Marginal Field with Longest Lateral Carbonate Oil Rim in Malaysia
Authors: Runtuwene Michael , Michael Jeremiah , Maruthanuthoo Kumaren 
Published: November 2020

Abstract
What constitutes a marginal field varies greatly but it is certain that extended time periods of low oil prices only magnify the challenges in developing such fields as it can stir even the largest reservoirs to go from commercially viable to marginal. E field is a marginal development project that must contend with all these unique set of challenges. For many years the project struggled to achieve minimum thresholds for funding. To develop the field during a low oil price market represented a cost-opportunity whilst presenting a value challenge. It is an extremely challenging thin oil rim reservoir development, under a complex and heterogenous geological environment, involving six long-to-extended reach wells in a loss-prone karstified carbonate.
While the well planning and design built upon the Operator's considerable experience in carbonate and long reach drilling in the region, the campaign remained unique as the characteristic resided beyond the envelope of what had been accomplished before. The key distrincions were the much longer lateral length and the combined scope to target the thin oil rim in addition to the gas cap, which was the first-time application in this area. This is where technology played a vital part, as an enabler for delivering a complex project in a competitive manner.
This paper briefly describes the planning stage of the campaign to ensure that the project was competitively scoped and delivered a fit-for-purpose solution, with focus on the technology implementation to address specific drilling challenges. Furthermore, it explains how a robust front-end loading, replication, and strong collaboration were key to making developable what was previously uneconomic.
Well-Test Deconvolution Analysis of Gas Condensate Layered Reservoirs
Authors: Geravand Roya , Foroozesh Jalal , Nakhaee Ali , Abbasi Mojgan 
Published: November 2020

Abstract
Well testing, especially in offshore platforms, is quite expensive and traditional well-test analysis are not capable of fully capture the boundary dominated effects from short-time, constant-rate pressure buildups. The complexity of the well test behavior of gas condensate layered reservoirs causes the pressure data from drawdown flow periods become too noisy, which makes it extremely difficult to obtain accurate results using conventional well-test analysis. Hence, only build-up periods with unit flowrate are used in pressure transient analysis. However, the duration of build-up tests are hardly long enough to capture the boundary dominated effects / faults. Luckily, deconvolution approach has overcome this issue through converting the whole test periods including multiple drawdown and build-up periods into a constant-rate pressure drawdown. This work aims to apply the variable-rate deconvolution approach to analyze a series of short well-test data obtained from the single-layer drill stem tests (DSTs) carried out in an offshore gas condensate layered reservoir. The results demonstrated that compared to the pressure derivative method, the deconvolution analysis provided us with more range of data and increased the radius of investigation, which enabled us to identify the boundary dominated flow regimes such as leaky/partially communicating fault, sealing fault / no flow boundary, as well as constant pressure boundary at late-times. In addition, we evaluated the performance of the treatment job conducted during some DSTs, in the same reservoir.
Development of an Assessment Procedure to Predict Local Buckling Behavior Using Probabilistic Method with Finite Element Techniques for Reeled Pipeline with Additional Features
Authors: Abdullah Sheralia Ufairah , Ngai Tommy 
Published: November 2020

Abstract
Reel-lay method is a fast, cost effective method of pipelaying for pipelines with an ideal diameter between 4" to 16". Reel-lay pipelines are plastically deformed to conform to the radius of the reel drum that is fixed on the vessel. The reeling operation requires a high level of engineering to ensure the pipe does not buckle nor have a high lift off on the reel or aligner during spooling and installation. This comes at the design level where the selection of wall thickness is driven by the requirements to avoid local buckling. The requirements imposed are taken from DNVGL-ST-F101 [1], a submarine pipeline systems’ standard that is widely used in the oil and gas industry in designing pipelines. However, the requirements are based on displacement control check equations with some fixed safety factors. The safety factor is designed to take into account the presence of mismatches in bending moment between pipeline joints and its system effect.
A refined assessment procedure for pipeline reeling have been developed within the industry and has been published due to the discrepancy in the minimum reelable wall thickness [[2]]. Finite element models are developed and analyzed to create a failure boundary between safe and unsafe regions using different combinations of mismatches. The reliability index is then determined using the failure boundary, which is then used to calculate the probability of failure. This method normally requires multiple FEA to create the failure boundary which can be very time consuming.
This paper outlines the probabilistic method which is an improvement to the past approach, where it firstly defines the probability of failure in calculating the mismatch. Finite element model is then developed and analyzed using finite element software Abaqus FEA [3] to verify that the level of safety associated with the method is met. The reeling studies carried out in this paper has shown that the probabilistic method requires far less analyses to be done and is able to analyze pipeline with features while still meeting DNVGL's requirement. This method also allows pipelines with different geometrical and mechanical properties such as transition design and bulkhead to be analyzed. This method normally requires only a single FEA.
Saturated Gas Hydrate Drilling Hazard Prediction Using Controlled Source Electromagnetic Method
Authors: Tharimela Raghava , Baillie Graeme 
Published: November 2020

AbstractNatural gas hydrates (NGH) are a significant hazard for drilling with direct implication on drilling and operation costs. Most often, the evaluation of the presence of gas hydrates is performed using seismic evidence such as bottom simulating reflector (BSR) and seabed indications such as seepages and pockmarks. Uncertainty in prediction of their presence is still large as the seismic signature is similar for both low and high saturated gas/hydrate accumulations, leading to instances where there is a BSR, but no significant amount of hydrates encountered when drilled. And conversely, where no BSR can be seen yet thick hydrate plugs were encountered while drilling. Seepages and pockmarks on the other hand indicate the presence of an active hydrocarbon system in the subsurface but does not indicate the extent/volume of the hydrocarbons that are the source of this gas migration. The only other alternative to confirm gas hydrate presence would be logging and direct core sampling. These methods, though reliable, can only provide point measurements and does not indicate the lateral distribution of hydrates. Adding more such point measurements would make the drilling operation more expensive.Electrical resistivity has a more reliable relation with saturation of hydrocarbons (Archie, 1940). The controlled source electromagnetic (CSEM) method that maps bulk subsurface resistivity remotely can be used as an efficient and cost-effective alternative to detect and determine the lateral extent of saturated hydrate accumulations. Integration of the resistivity volume from the 3D CSEM dataset with seismic and other geophysical information will enable one to distinguish between low saturated and saturated hydrate bearing sediments, significantly reducing uncertainty in hydrate prediction. This would help in better selection of subsurface drill location and minimizing the need for additional logging and direct core sampling priori to drilling.In this paper we discuss about the CSEM method specific to hydrate mapping along with case examples showing how the inclusion of CSEM in interpretation improves the understanding of the hydrate system in order to make a better hazard prediction.
First Successful Deployment of Improved Flowback System for a Deepwater Wireline Micro-frac Test
Authors: Zhang Tingting , Abd Rahim Mohd Helmi , Kim Igor , Ting Angelina , Moronkeji Dee , Hardikar Nikhil Prakash , Funes Daniel A 
Published: November 2020

Abstract
In a typical waterflooding philosophy, water injection is often constrained by the in-situ stress of the overlying geological seal, in order to avoid out-of-zone injection and ensure reservoir fluid containment. Direct measurement of in-situ stress from wireline Micro-frac testing is insightful as compared to a conventional leak-off test (LOT) conducted at the casing shoe, due to the smaller volume and lower injection rate used. Unlike the conventional LOT, Micro-frac tests can be performed at discrete and multiple intervals in one wireline run, away from the casing shoe.
In 2017, Shell Malaysia Exploration and Production (SMEP) conducted the first wireline Micro-frac test in a caprock shale, in a deepwater injector well, offshore Malaysia. The job was successfully executed with an improved design of the flowback mechanism, using a combination of a small volume pump and a drawdown chamber. While the small volume pump provided the advantage of accurate volume/rate measurement, the modified drawdown chamber setup provided a constant flow rate, to aid in a more accurate fracture closure pressure interpretation. The improved setup was the first successful application of this device for the purpose of Micro-frac. Both the methodologies showed good and comparable results, thereby adding higher confidence to the interpretation of fracture closure pressure.
A workflow has been developed to ensure successful execution of the logging job. Pre-job modeling was completed using offset well data to derive formation mechanical properties as well as in-situ stress profile. This information was then used to characterize formation breakdown pressure, selection of test intervals and optimum straddle packer positioning. Learnings from the test conducted at the first depth station were used to optimize the number of cycles for the subsequent stations. In addition, an operational decision tree was developed to assess the number of cycles required and contingency criteria.
The paper presents an improved flowback design using the drawdown chamber as well as the operational challenges in a deepwater environment. The methodology provided a reliable estimate of fracture closure pressure in a non-permeable formation. Results have been used to update the water injection envelope, in an effort to avoid undesired out-of-zone injection.
Characteristic of Tropical Storm Pabuk Based on Field Measurement
Authors: Shamsudin Mohd Azim , Latheef Mohamed , Abdullah Mohd Nasir , A. Rahman Azam , Rashid Rosedianty Marsilla 
Published: November 2020

Abstract
Tropical Storm (TS) Pabuk which occurred in South China Sea during the Northwest Monsoon season of 2018-2019 is a rare storm event. Even though it was originally considered weak, it was able to enter and remains active in the 5 degree latitude of weak Coriolis zone, then track further north, make a short land crossing before ending in Andaman Sea. At its early formation, it was in tune with the incoming monsoon's cold surge which perfectly align with the storm outer circulation that enable it to amplify like a little push that spun a spin-top going faster. The waves measured during this storm far exceeds the waves conditions associated with a 100 year Return Period (RP). In addition to being larger, they are also much steeper than the waves contained in the SEAFINE hindcast database spanning back over the past 59 years. However, interestingly, correlating the generated waves with the local wind field showed that at the locations where the data originated, the peaks in wave conditions are contributed by swell.
Water Intake Riser – Hydrodynamic Damping Modelling for Fatigue Assessment
Authors: Minguez Matthieu , Zhao Wenhua , Gao Zhenguo , Efthymiou Mike 
Published: November 2020

Abstract
The Prelude experience has underlined the potential strong impact of both the hydrodynamic damping and any potential superimposed current to properly assess the Water Intake Riser life time, refer to Minguez & al. (2020). This effect, resulting from the considered hydrodynamic modelling, remains qualitatively suggested within the different riser design standards (e.g. either the DNV-GL-RP-C205 2017 or the ISO-13628-7 and ISO 19902 2007) but no quantitative recommendations agree on the way to properly address such a topic. The proposed numerical developments underlined the gap between the different Best Practices and the impact in terms of fatigue assessment. The different recommended damping models are considered and experienced to assess the quantitative impact on fatigue assessment.
Based on this critical review, a large-scale model test focusing on a simple riser response is proposed to position the different existing hydrodynamic models. This has been done by imposing forced motions to a rigid cylinder mounted under a spring system. The system, free to move, is plunged within a basin in which different current speed and direction are imposed. Both loads and dynamic responses of the model have been monitored.
The numerical developments proposed in the frame of this research suggest both any damping and drag empirical formulation to properly address such fatigue concern from engineering point of view.
This work finally recommends that caution be exercised when the DNV guidelines and the International Standard are followed due to the contradiction of the recommendations with the experimental evidences reported in this study.