bluuebunny/crossref_metadata_2025_split huggingface dataset:
Risk Management Study on Compaction and Subsidence for CO2 Storage Project
Authors: Ali Siti Syareena M , Widyanita Ana , Jalil M Azran b A , Kantaatmadja Budi Priyatna , Mansor M Nezam , Ern Kevin Teng Ging , Musa Ikhwanul Hafizi , Kamaruddin Nik M Fadhlan Nik , Zamberi M Shahrul Amir 
Published: March 2018

Abstract
As part of ongoing study for CO2 sequestration in Sarawak basin, offshore Malaysia, storing of CO2 in depleted gas reservoirs is one of the options besides deep saline aquifers and dry structures. These single options have their own advantages and challenges. Most of the depleted giant gas fields in Sarawak basin experienced pore collapse during later period of production life. The magnitude and the severity of pore collapse depend on effective stress changes and reservoir compaction behavior. Most of these carbonate reservoirs in Sarawak have been producing for more than 10 years and have undergo pore collapse to various degrees at depleted reservoir pressures. Core studies have indicated possible pore collapse to happen from 900psi to 1590 psi of abandonment field pressure. It was observed from the core studies that carbonate facies with predominantly vuggy and mouldic porosities varying in the range of 20 – 35 % that are more susceptible to collapse. The pore collapse consequently resulted in reduction pore volume, destruction of permeability, reservoir compaction and subsequently surface subsidence. This could further impact the existing surface facilities (platform sinking), casing integrity in existing wells and possible fault reactivation jeopardising structural integrity.
Nevertheless, some of the carbonate reefal gas reservoirs in Sarawak basin have sizeable capacity presenting attractive opportunity for utilizing them as potential storage sites once they reach the abandonment stage. However due to the above enumerated risks associated with the possible pore collapse scenarios, a thorough screening and selection of storage reservoirs is required. This paper attempts to present various selection criteria evolved for screening, selection of potential storage sites and a case study, focusing on overall 3D/4D Geomechanics workflow for reservoir compaction and seabed subsidence, data calibration and other criteria that helps for final development program of CO2 geological storage site.
Geo-Engineering Integrated Fracturing Design Workflow and Application in Sichuan Basin of Southwestern China
Authors: Li Yanchao , Yin Congbin , Qian Bin 
Published: March 2018

AbstractIn the past five years, shale gas development had made great progress in Longmaxi shale of Southwestern China. Different from the North American shale, the Chinese shale reservoir has the characteristics of deep and multi-stage tectonic movement, which presents a huge technical challenge for economic development. Especially, great horizontal stress difference resulted it was difficult to create complex fracture network during hydraulic fracturing. So it is vitally important to provide a workflow of geo-engineering integrated fracturing design for Chinese shale economic development.In this paper, a workflow of geo-engineering integrated fracturing design is proposed to optimize fracturing parameters, which is based on geology modeling and formation quality evaluation. This workflow contains stress and natural fracture prediction and modeling, perforation sweet spot optimization, stimulated fracture network and productivity prediction, treatment parameters optimization, and fracturing design evaluation. In order to improve the use of convenient and complex data processing of fracturing engineers, the simulation system of shale stimulation (CQ-4S) is developed which is based on this workflow.The applications of workflow and system during more than thirty shale gas wells in Southwestern China illustrated that the workflow and system could effective optimize design of shale stimulation, which contains some advice of perforation sweet spot, cluster spacing, treatment volume of fluid and proppant. The predicted fracture network had good agreement with microseismic data, and predict well performance also had good agreement with real-measured results. According to fracturing analysis and evaluation of more than thirty cases with this workflow and system, we also recognized that there were 13 geoengineering parameters which determined fracturing effectiveness of Chinese shale gas.The results of this paper provide some guidelines for shale gas stimulation design and evaluation in Southwestern China, which is also can provide reference for other emerging shale gas development.
Gas Recovery Through the Injection of Carbon Dioxide or Concentrated Flue Gas in a Natural Gas Hydrate Reservoir
Authors: Peter Englezos , Messah Mani , Chau Jacky 
Published: March 2018

Abstract
Because CO2 hydrate is stable at pressures lower than those required to stabilize hydrates of CH4 when compared at the same temperature the injection of CO2 into gas hydrate reservoirs was proposed a while ago as a method to recover methane. The added advantage of such a technology is the simultaneous sequestering/storage of CO2 captured from fossil fuel power plants or other significant point sources of CO2. Recent reviews on the subject have provided an account of the laboratory and theoretical work on this topic. The reviews highlighted the need to further elucidate the dynamics of the exchange process and provide information needed for the design of industrial scale facilities. In this work, the kinetics of the CO2/CH4 exchange process are investigated in a 5.3 L laboratory crystallizer (reservoir) equipped with ahorizontal injection tube with 24 exits into the packed bed of silica sand particles. Preliminary experiments conducted using this apparatus and also with a high pressure calorimeter indicate that in lab experiments there is some residual water and that the extent of the exchange process is limited. Even if the CH4 recovery is optimized there is aneed for a CH4/CO2 separation plant to enable a complete cyclic sequence of CO2 capture, injection and CH4 recovery.
New Workflow in Reservoir Modelling - Incorporating High Resolution Seismic and Rock Physics
Authors: Ghosh Deva , Babasafari Amir , Ratnam Teresa , Sambo Chico 
Published: March 2018

Abstract
In field development and production, a reservoir model is a key element in the successful performance of an oil and gas field. Well logs and core data have high vertical resolution whereas seismic data has poorer resolution vertically. However, 3D seismic data has very high horizontal resolution. We will take this into account while proposing the new methodology.
Depending on wells only we can have a hi-res model far higher than what we actually need. However, in between the wells any meaningful extrapolation is flawed. Using geo-statistics through kriging algorithm and variography leads to non-geologic reservoir models. One particular process which is highly undesirable is to throw any valid well info and upscale it such as to fit the seismic. This results in a model that is inherently flawed. The important aspect of the new methodology is to follow up the seismic stochastic inversion together with a suitable rock physics modelling to achieve high resolution (reservoir scale) of different litho-facies discrimination.
In this study first a robust rock physics model is performed for not only shear velocity log prediction at not having shear log wells but also to more appropriate litho-facies differentiation at well locations using seismic elastic properties (AI vs. Vp/Vs). Afterwards, seismic pre-stack stochastic inversion is carried out to populate different types of litho-facies between the wells. Eventually, the distribution map of pay zone facies is resulted.
An ANN-Based Framework For Rapid Spectral Fatigue Analysis of Steel Catenary Risers
Authors: Hejazi Rasoul , Grime Andrew , Randolph Mark , Efthymiou Mike 
Published: March 2018

AbstractA simplified framework is presented in which an existing artificial neural network (ANN) based tool for critical stress range prediction is used in order to rapidly assess the fatigue life of a steel catenary riser (SCR). The simplified approach considers the first-order motions of the hosting floater (heave, pitch and roll motions) and irregular sea-states to assess the critical stress range within the touchdown zone (TDZ) of the SCR. Stress transfer functions are generated that approximate the SCR TDZ critical stress range due to vertical motion at the SCR hang-off point. The motion response amplitude operators (RAOs) and transfer functions are then combined to generate the SCR TDZ stress spectra and hence assess accumulated fatigue damage for all potential sea-states at the floater location. The fatigue lives of two large diameter SCRs subject to a sample irregular wave scatter diagram are calculated using the simplified framework. The results are then compared with those determined via a state of the art commercial software that uses a dynamic time-domain finite element (FE) analysis with rain-flow cycle (RFC) counting and shown to provide a good agreement. It is an important result as the time required to run the simplified analysis is an order of magnitude smaller than the more rigorous analysis (minutes versus hours). It demonstrates the usefulness of the simplified approach at the early stages of an SCR design where a large number of simulations are needed for sensitivity studies in order to select an optimized concept.
Intelligent Near-Bit Reamer Affords Same-Trip Drilling, Hole Enlargement and Rathole Reduction for Optimal Deepwater Well Construction
Authors: Valverde Eddie 
Published: March 2018

Abstract
Simultaneous drilling and hole enlargement in deepwater wells helps set casing strings deeper in the well. Common BHA designs place an underreamer above the MWD/LWD package, which ensures reliable mechanical activation of the underreamer, but also leaves up to 200 feet of undergauge rat hole to TD. An intelligent underreamer is presented with RFID and pressure cycle activation capabilities. Placed closer to the bit, this underreamer minimizes the rat hole to ensure deeper casing setting.
The intelligent drilling reamer is a concentric mass-balance underreamer that enlarges wellbores below casing restrictions. The reamer simultaneously drills and enlarges when deployed with rotary-steerable systems or rotary BHAs. Unlike ballactivated underreamers, the intelligent reamer is activated via RFID, in which RFID tags are pumped downhole to transmit instructions to an electronic reader on the reamer. The reamer can also be activated with a pressure cycle, which opens or closes a solenoid-operated valve to lock or unlock the reamer. With this dual actuation feature, the tool can be installed just behind the bit, where it significantly reduces rathole length.
An operator working offshore Malaysia deployed the intelligent underreamer to enlarge a highly deviated, slimhole wellbore from 6-¾ in. to 8-½ in. The tool was run in the lower part of the directional BHA, near the bit, to minimize the rathole. A set of RFID tags was dropped into the drill string at the same time that the pressure pulse activation sequence began. The RFID tag activation code was not received at the expected time, an indication that the tags were not able to easily pass through the turbine-driven MWD tools. However, the reamer was activated by the pressure pulse sequence and the rathole elimination operation commenced.
The reamer reduced the rathole length from 180 ft to 10 ft (55 m to 3 m), allowing the operator to achieve its completion and reservoir inflow requirements without changing drilling practices or replacing any BHA components. The operation eliminated the need for a dedicated run to enlarge the hole. The single run also minimized openhole time, which reduced borehole instability risks. In total, this single-trip drilling and reaming run reduced rig time by approximately 20 hours, equivalent to a cost savings of approximately USD125K.
The intelligent reamer is the only one of its kind capable of actuation via RFID tags or pressure pulse cycling, which provides on-demand control for nearly unlimited activation and deactivation when tripping and drilling. It also provides a backup activation option when the primary RFID method fails. The tool's RFID-activated automatic battery savings mode increases battery life by up to four to eight times, which ensures longer reaming runs in the same trip.
Improved Reservoir Characterisation in Malay Basin through Seismic Stratigraphy and Rock Physics Modelling
Authors: Rahman Ahmad Sharif Abd , Fuad Muhammad Izzuljad Ahmad 
Published: March 2018

Abstract
Discovering easy hydrocarbon reserves in Malaysian Basins particularly in the Malay Basin has become the story of the past. Most of the remaining reserves are now anticipated to be found in more difficult geological settings; such as in channel sand, stratigraphic traps, or in thin beds. This is not to say that there is zero possibility of discovering new hydrocarbon reserves in the more "easier" anti-cline structural setting, but most likely the new reserves would be at deeper intervals below the current typical operating depth of within 3 km below the sea bottom. The deeper reservoirs would require larger investment and at the same time exposing exploration and development ventures to higher risks as the likelihoods of penetrating the overpressure zones in the Malay Basin at deeper interval are much higher.
The main objective of this paper is to establish a workflow concept of a seismic modelling platform that utilizes deterministic rock physics to derisk and reduce uncertainties in the reservoir characterization. This general objective entails three specific goals: 1) to model geological scenario from seismic data, in order to identify more likely geological scenarios among the all avaible geological possibilities; 2) to discover and incorporate rock physics diagnostic and modelling as the link between geological and geophysical parameters; 3) to apply the proposed workflow in an actual dataset (a possible delta fan lead in Malay basin) to verify its applicability.
A field in the early development stage has very limited data: a little well data, seismic data, and some geological observation. Reservoir forecasting in this stage is one of the most important tasks for future decision making. A deep lead located in half graben setting within Malay basin (Figure 1) is used for verification of the workflow, and the study starts from the beginning stage of stratigraphy modelling.
Moho Nord, A Complex Integrated Project
Authors: Blarez Emmanuel 
Published: March 2018

Abstract

Objectives/Scope
With two different reservoirs – Miocene and Albian; a development combining brownfield and greenfield; two production platforms – a Floating Production Unit (FPU) and a Tension Leg Platform (TLP); and the collapse of the oil price during the project execution phase … Moho Nord operated by Total E&P Congo is a highly complex project. The objective of this paper is to show how Total managed to ensure the success of the project phase.

Methods, procedures, process
The development scheme of Moho Nord is above all an optimal response to the constraints imposed by the different reservoirs. Then, Total had to efficiently supervise this complex project during the industry downturn, while maximizing the local content in Congo, drawing on the best available technologies to reduce the environmental impact of the new installations, and developing innovations notably to be able to simultaneously drill, intervene and produce the complex Albian reservoirs.

Results, observations, conclusions
Total successfully completed this large and complex project, including the first TLP for the Group in Africa. Production started in March 2017 less than four years after the Final Investment Decision (FID). Three floating units are involved: the already existing FPU Alima and the new-build FPU Likouf with a typical subsea production layout, and the TLP with surface trees. Production is sent onshore to the existing terminal at Djeno.
To meet the challenge of a dual development comprising brownfield and greenfield sites, Total created an integrated muti-discipline team to work on the upgrade of FPU Alima and its subsea network, modifications to the Djeno terminal, and the construction of the new FPU and TLP units. Packages for Umbilicals, Flowlines Risers (UFR), Subsea Production System (SPS), Geosciences, Drilling, and Support services were shared across the whole development.
The main contracts were signed in 2013 before the oil price collapse and Total had to rely on the expertise and creativity of its teams and contractors to manage the project through difficult times, without compromising success and safety.

Novel / additive information
With the Moho Nord project Total has demonstrated its capacity to manage a large, complex brownfield and greenfield project to time and budget even in a difficult economic climate.
Software for Automated Visual Assessment of Coating Damage
Authors: Tan Wei Chian , Chen I-Ming , Goh Phoi Chin , Tan Hoon Kiang 
Published: March 2018

Abstract
Current visual assessment of coating damage is performed by experienced inspector. This leads to variation in procedures and decisions among inspectors. Disagreement caused during assessment introduces issue of low reliability and repeatability of assessment results. A software that automatically identifies and determines percentage of defective areas in a given image is presented. Tested on a dataset of structural defects, outcome of the software is validated against answers provided by engineers and inspectors. The software requires an image of coating surface and hints on regions of interest as inputs. Users provide hints by clicking few times on regions they are interested (known as foreground) and not interested in (known as background). With built-in intelligence, the software scans the image and identifies defective areas by comparing colour difference between each pixel and hints user provided. If colour value of a pixel is found to be closer to hints in foreground, it is labelled as defective area and vice versa. Next, percentage of defective area in the image is determined and reported. Dataset of structural defects (http://xiscobonnin.github.io/resources/#datasets) with 73 images was used for experimental evaluation. These images come from wide range of engineering scenarios and contain different levels of coating damage. Wide variation that exists in the images would allow comprehensive understanding of performance of the software. Without prior learning, given each image, users provided hints by clicking few times (less than 10) on foreground and background. Machine (or computer) took over the analysis subsequently using algorithm developed based on colour information. Outcome from the software was validated against decisions made by engineers and inspectors. Results are promising with more than 90% of the defective areas successfully identified and in agreement with inspectors’ judgements. Reported percentage of defective areas for each image is also aligned with manually estimated value. This demonstrates that the developed tool is capable of improving process of visual inspection of coating surface. With current state of the art, user's hints have been proven to be very useful in guiding machine or algorithm to segment the image into foreground (region with coating damage) and background (irrelevant region). However, challenges remain for difficult situations such as colour of background being close to foreground and machine is unable to differentiate. Developed software is able to assess condition of coated surface quantitatively based on given image. This minimises the chance of argument over qualitative assessments during inspection. Having standardised tool for assessment would also allow comparison among existing cases. This serves as first step towards capture of experience in the industry through automation. Refinements such as threshold adjustment can be made subsequently to minimise difference between decision made by the software and experienced personnel.
Numerical Approach for the Prediction of Formation and Hydraulic Fracture Properties Considering Elliptical Flow Regime in Tight Gas Reservoirs
Authors: Hossain Md Mofazzal , Al-Fatlawi Omar , Brown Dominic , Ajeel Mohammed 
Published: March 2018

AbstractAs tight gas reservoirs (TGRs) become more significant to the future of the gas industry, investigation into the best methods for the evaluation of field performance is critical. While hydraulic fractured well in TRGs are proven to be most viable options for economic recovery of gas, the interpretation of pressure transient or well test data from hydraulic fractured well in TGRs for the accurate estimation of important reservoirs and fracture properties (e.g. fracture length, fracture conductivity, skin and reservoir permeability) is rather very complex and difficult because of the existence of multiple flow profiles/regimes. The flow regimes are complex in TGRs due to the large hydraulic fractures near the wellbore, combined with low matrix permeability and reservoir heterogeneity; and consequently the interpretation of well test or pressure transient data using the classical approaches usually used for conventional reservoirs can produce wrong results with high level of uncertainties. In addition, the time required to achieve radial flow regimes for such tight reservoir, as key condition to use classical approaches, is impractically long and not feasible from the context of both economic and practical operation viewpoint. These inherent causes and the operating limitations require amendment of the well test technique to analyse linear or elliptical flow regimes to accurately estimate the reservoir and fracture properties.This paper proposed a simplified numerical approach to predict the reservoir and fracture parameters based upon well test or production data from hydraulic fractured vertical well in tight gas reservoir considering elliptical flow regime. Emphases are given on the development of simple computation tool that can be used as a handy, efficient and accurate tool to supplement the need for commercial simulators; yet can provide with estimation of reservoir and fracture properties with high level of accuracy especially in the case when limited pressure transient data is available.
Preventing Dropped Objects on Offshore Units and Installations
Authors: Corcoran Chris , Stroubakis Demetri , Sarthy Ahmad 
Published: March 2018

Abstract
ABS has published the first international class standard on the subject of dropped object prevention. The objective is to promote offshore safety through improved asset integrity management and the use of inherently safe design principals. This paper serves to increase dialog among owners, operators and manufacturers by presenting the drivers behind the development of the ABS standard and examples of what can be accomplished to achieve a dropped object free working environment.
Dropped objects are among the top 3 causes of injuries in the work environment and accounted for 14% of fatalities in the US Upstream Oil and Gas Industry from 2003-2014. A summary of statistical information will be presented along with the results of research on regulatory requirements and current design standards. A brief history of dropped objects in the workplace as they relate to the historical development of safety systems will be discussed and the content of the ABS Guide for the Prevention of Dropped Objects on Offshore Units and Installations will be presented.