bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of High Pressure High Temperature Condition on Well Design Development in Offshore Vietnam
Authors: Nguyen Truong H. , Bae Wisup , Hoang Nhan T. 
Published: March 2016

AbstractTwo fields are of Hai Thach and Moc Tinh of the Block 5.2 and Block 5.3 in offshore Vietnam have been discovered and exploited of the oil and gas production since the middle 90s. At this time, many contractors will be drilled wells development in the fields with 16 wells by using Tender Assist Drilling (TAD). There are high-temperature, high-pressure (HPHT) in the two fields with the bottom hole temperature range from 140 °C to 175 °C and the bottom hole pressure range from 10,000 psi to 11,500 psi. Through drilling and construction wells have been met many problems related to high pressure high temperature wells. Especially in the discovery well and appraisal wells in high pressure, high temperature reservoir (HPHT), There are a lot of incidents and operating technical problems during drilling. One of the problems during drilling is the gas influx into the wellbore due to the abnormal pore pressure, shallow gas, fluid loss due to the fracture pressure and pore pressure is very narrow margin, stuck down hole equipment in the wellbore due to high differential pressure between hydrostatic pressure and pore pressure and another problem was related to drilling mud and cement. At the stage of wells developemnt, the biggest challenges deal with design HPHT wells, which are required to high efficiency during drilling, construction wells and also require to bottom hole assembly working for a long time and a safe in the reservoir condition of high-pressure, high-temperature. Although the principal design HPHT wells was not different to principal conventional wells, but that well was still potentially risky and very challenging because of the strict design HPHT wells have not much been to choice materials and equipment. This study has been presented in detail the difficulties, solutions, and the effect of high –pressure, high-temperature on wells design development in HPHT conditions such as Casing design and selection grade, the differential pressure between reservoir pressure and fracture pressure is a narrow equivalent circulating density (ECD) management, laboratory the effect of temperature on rheological properties and model behavior of drilling fluid by using V35 fann, selection drilling mud in drilling wells HPHT conditions. Also techniques have been shown the lesson learned to drill and construct wells in high pressure, high temperature condition in offshore Viet Nam.
Technology Qualification for Small Diameter / Thickwall Reelable DSAWL Linepipe
Authors: Hall Stephen , Connelly Martin 
Published: March 2016

AbstractTough market conditions have seen the price of oil drop by circa 50% between mid 2014 and early 2015. This drop and subsequent uncertainty have seen the oil and gas industry concentrate on the cost of designing, installing and operating pipelines. A critical process for the industry is the procurement, manufacture and installation of appropriate linepipe. The method of installation is often dictated by the pipe size and the water depth that the pipe is to be laid in, however there are times when the choice of lay method is due to vessel availability and relative costs for each technique.The industry regularly uses seamless pipe for installations by reel lay, however submerged arc welded linepipe (SAWL) has successfully been manufactured, installed and commissioned via this method and can realise significant cost reductions. SAWL material installed via the reel lay method has not been fully characterised to understand the material properties during the installation process and no formal characterisation program was undertaken for the successfully installed projects. To combat this lack of knowledge a technology qualification following the basic principles of DNV-RP-A203 was carried out to research the strain behaviour of pipes intended for reel-lay installation.This paper outlines the technology qualification process used to characterise the behaviour of a 406.4mm OD × 22.2mm WT SAWL linepipe material that was subjected to full scale reeling simulation using a fixed end cantilever type reeling simulator. A comprehensive test program was developed and carried out to provide the characterisation of the linepipe base material and longitudinal weld, both before and after full scale simulated straining and ageing. The test program was set up to prove the material properties against DNV-OS-F101 Supplementary Requirement P and the results of these tests are presented hereafter.The work presented in this paper will provide a basis for future investigations into the strain behaviour of pipes of different sizes and wall thicknesses or different straining cycles intended for reel-lay installation.
Single-Trip Multizone Sand-Control System Deployed on Hydraulic Workover Unit in Offshore Malaysia
Authors: Aripin Izura , Faisalluddin Teuku , Allapitchai M Shahril Majid , Hamidy Hudzaifah Zol , Ghazali Ikmal Hakim , Ab Latif Ahmad Syauki , Govinathan Kesavan , Priatna Oktaf 
Published: March 2016

Abstract
This paper presents a case history in which a single-trip multizone sand control system was successfully deployed in Malaysia using a hydraulic workover (HWO) unit. The well consists of two (2) zones which were both treated and completed in a single-trip gravel pack system. This paper discusses in detail the design selection and operation, which includes the challenges faced and mitigation to overcome the challenges. All operations involved were completed with a significant time and operational cost saving to the operator.
This was the first successful single-trip multizone installation using HWO globally. The sustained prolific oil production from this well affirms the success of the completion and gravel pack treatment method. These positive results highlight the importance of operator technical/operations personnel and service providers working as a team to develop the most appropriate solutions to the technical and operational challenges encountered.
New Development in Wireline Logging Under Activated Pressurised Mud-Cap Drilling Enabled Fractured Carbonates Evaluation
Authors: Kyi Ko Ko , Nathan Kumar , Haddad Sammy , Wa Wee Wei , Lee Andre Ooi Ken , Hui Gabriel Houng Nai 
Published: March 2016

AbstractPressurised Mud Cap Drilling (PMCD) is a variation of Managed Pressure Drilling (MPD), that involves drilling with no returns to surface and where an annular fluid column, assisted by surface pressure, is maintained above a formation that is capable of accepting fluid and cuttings. The application of this technology in drilling fractured reservoirs has been long established. However, formation evaluation techniques in such reservoirs are yet to be established due to the challenges that are associated with wireline logging in such a drilling environment.Concerns related to total loss circulation, potential gas migration, and unsustainable fluid logistics have led to the perception that wireline logging operations during PMCD are impossible or logistically impractical. Apart from that, there are also concerns with regards to data quality due to the uncertainty of borehole conditions. Conveying wireline tools via drill pipe is also ruled out as the Rotating Control Device (RCD) sealing elements are not able to seal on wireline which is outside the drill pipe in Drill Pipe Conveyed logging system.This work focuses on a new development that allows wireline logging under activated PMCD condition in wells drilled through carbonate gas reservoirs. The main challenges in evaluating such reservoirs are obtaining representative reservoir fluid samples and identifying fluid contacts needed for reserves booking. This paper will present the new developments and procedures on both operational and technical aspects. Field data and work flow will be used to demonstrate how the new development enabled the successful evaluation of fractured Pinnacle Reef carbonate reservoirs under total loss circulation and PMCD activation.This paper discusses the operational details on wireline logging with activated PMCD, challenges encountered due to borehole conditions as well as acquisition results, lessons learnt, recommendations and conclusions.
Cased-Hole Reservoir Fluid and Rock Evaluation – What Can Be Done if This Was the Only Option Available?
Authors: Kyi K. , Haddad S. , Chouya S. , Ooi A. 
Published: March 2016

AbstractReservoir fluid characterisation in cased-hole is often challenging especially in thinly laminated and low permeability formations. Obtaining representative reservoir fluid samples is an important step in verifying fluid type and properties in addition to reserves booking requirements. Downhole fluid analysis (DFA) provides critical information on early confirmation of fluid type, while samples are used in the lab to provide PVT and physical properties of the reservoir fluid.There are two (2) main ways to obtain fluid samples in cased-hole environment: either through subsurface sampling via wireline downhole sampling tool (WFT) or surface sampling via well testing full term (DST). Depending on the test objective, each method has its pros and cons. Subsurface sampling is normally performed in open hole. However, wellbore conditions and formation characteristics sometimes prohibit logging in open hole, hence sampling can only be performed in cased-hole. This also applies to wells which had been cased earlier than expected due to operational constraints. Conventional DST in cased-hole can be prohibitive due to many factors including cost especially if multiple layers have to be tested, not to mention environmental concerns restricting flaring.This work depicts the successful fluid sampling strategy based on case studies in East Asia reservoirs. The paper will also discuss a proposed best practice that is supported by field data.
Quality Control for Interpreting Geophysicists of Common Image Gathers and the Velocity Model in Offshore Salt Dome Basins
Authors: MacShane Terry 
Published: March 2016

Abstract
Subsalt imaging is an important process for exploration of offshore basins. These salt basins present a technical challenge for present day imaging methods. Strong lateral velocity variations, irregular salt bodies, and subsalt structure imaging require quality control during the image processing phase. Methodologies and techniques are available for interpreting geophysicists to quality control prestack common image gathers (CIGs) and the velocity model (VM) in depth. The three dimensional (3D) SEG/EAGE Salt Model (Ober et al.,1996) is an ideal dataset to demonstrate the process because it was designed to contain major complex features common to offshore basins.
The SEG/EAGE C3 Narrow Angle Subset Salt Model is used to demonstrate the methodology employed for quality control, CIGs, and the interval velocities in depth used in imaging the data. The methodology involves residual move-out semblance panels based on RHO/percentage (RHO - Greek typography representing percent error) move-out trajectories. Velocity percentages are generated in the image domain to measure the curvature of reflection events on migrated offset image gathers. The curvature of offset image gathers depends strongly on the velocity used in the migration. If the velocity is correct, the reflection events on offset image gathers are horizontally aligned. If the velocity is incorrect, then the reflection events will show depth residual move-out.
Techniques are available for depth imaging that allows the interpreting geophysicist to respect the geologic concepts by controlling the quality control of the CIGs and the VM during the depth imaging processing phase. This includes salt dome basins where the depth imaging technology is most challenged.
Interpreting geophysicists are searching for solutions that balance the divide between turnkey on-time turnaround depth imaging processing and respect of the geology.
BOP Shearing: FEA Modelling with Void Coalescence Ductile Fracture Theory
Authors: (Ted) Cole Edward H. 
Published: March 2016

Abstract
Blow-out preventer (BOP) shearing is a critical element of well control affecting both safety and environment. BOP shear testing traditionally shows a wide range of actual pressures to shear for any given tubular size and grade. Universal predictor formulas are often dramatically conservative in order to cover outlier data in shear testing. The drilling industry needs improved theoretical understanding of the BOP shearing process. A correct constitutive model for material behavior is critical for theoretical modeling. The Extended Mohr-Coulomb (EMC) model is viable in studies of ductile fracture, but determination of the EMC coefficients for particular material can involve extensive specialized material testing. Theoretical work has focused on developing EMC coefficients with an intermediate level of theory involving cell modeling of void coalescence for high triaxiality (tensile dominated) stress conditions. With this method, EMC coefficients can be determined from standard material tensile tests. This method shows promise for practical application to prediction of BOP shearing of drilling and completions tubulars.
Material tests were performed on drill pipe remnants after full-scale BOP shearing tests were performed. This material test data was used with void coalescence theory to determine ECM coefficients which were then used in Finite Element Analysis (FEA) simulations of the full-scale BOP shears. The FEA used an element death technique to simulate pipe fracture and crack growth. In this initial phase of study, comparisons of theoretical predictions of maximum shearing force were mixed, but much was learned about the mechanism of BOP pipe fracture. Variation in properties from multiple material specimens taken from both adjacent locations and remote locations of the same drill pipes also indicated a larger than expected local variation in material properties. This fact, along with comprehension from the FEA that only a small zone of the drill pipe is involved in the shear initiation process suggests the cause of the wide variation which is observed in full-scale BOP shearing even when multiple shears are performed on a single pipe. Extensions of this study plan to investigate sensitivity of the theoretical model to characterization of the plastic strain hardening model, and will explore the use of a new void coalescence theory which has been developed for low-triaxiality (shear and compression dominated) ductile failure.
Multivariable Threshold-Processing Workflow Provides Comprehensive Cement Evaluation for Effective Well-Barrier Assessment in Plug and Abandonment Applications
Authors: Imrie Andrew , Heeley Beverley , Foianini Ivo 
Published: March 2016

Abstract
This paper presents a cement-evaluation workflow that encompasses the use of multiple measurement thresholds, proving that data processing with the use of logical discriminators can determine true cement-bond conditions with the use of conventional diagnostic tools.
The algorithm filters raw and derivative acoustic data through various predetermined thresholds to discriminate well intervals that possess proper cement bond and vertical coverage. Should data associated with a well interval pass through all the chosen logical filters, the interval is flagged as having the necessary cement presence and bond to be considered an isolating annular barrier. The logical thresholds are operator-defined, enabling a customizable assessment of any cement type, regardless of operator standards, legal codes, or environmental regulations.
The service was recently implemented in various wells where the customer required a decisive assessment to determine if a cement bond was minimally present prior to proceeding with abandonment. Their previous experiences with well-integrity diagnostics had resulted in contradictory information, requiring additional intervention work to help ensure zonal isolation. The interpretation workflow was able to indicate the presence of a minimum 11 ft of continuous cement and 100 ft of total cement behind the 7 5/8-in. OD production casing, which was one of the customer's well-integrity standards. The processed acoustic response, acquired with a cement-bond log tool and ultrasonic scanner, is presented in binary form, which clearly distinguished several intervals where annular cement complied with the various technical and legal variables that the client adopted.
By eliminating the inconclusive nature inherent to cement evaluation, the new interpretation solution can rapidly serve operators with a simplified result, enabling faster decision making to determine whether or not remedial work is required. This routine can be especially valuable to asset decommissioning and new well drilling, where more assertive decisions regarding well-barrier integrity can result in operational efficiencies.
Advanced Cryogenic Structural Collapse Analysis CSCA - Part II: Cryogenic Flow and Structural Cooling
Authors: Pujol Joaquim , Kleiveland Rune N. , Lileheie Nils. I. , Holmas Tore , Amdahl Jorgen 
Published: March 2016

Abstract
Floating Liquefied Natural Gas (FLNG) is the term used for producing, processing, storing and offloading natural gas at sea. Cryogenic hazards represent a significant safety risk for assets and personnel, but current methods to estimate the cryogenic risks are still coarse.
Lloyd's Register (LR) has taken the initiative to develop a more advanced approach to Cryogenic Risk and Cryogenic Spill Protection (CSP) Optimization: the Advanced Cryogenic Structural Collapse Analysis (CSCA). The CSCA is a numerical approach that fully couples 3D CFD cryogenic flow modelling with 3D FEM thermal and structural response to prevent structural escalation.
This paper describes the first and second step of the CSCA: the cryogenic flow modelling with CFD and the thermal response of the load bearing structures with FEM to one representative cryogenic load. The CFD solver used is KFX-LNG by ComputIT and the thermal code is FAHTS by USFOS.
The capabilities, tests and state-of-the-art of KFX™-LNG for cryogenic flow modelling are discussed. The paper also describes the capabilities, tests and state-of-the-art of FAHTS for thermal response of main load bearing structures. The paper then concludes with a cryogenic analysis with KFX-LNG and FAHTS of an accidental LNG leak on a realistic offshore module. The CSCA numerical approach to solve the potential structural collapse of the offshore module (non-linear stress-strain analysis) is not described here.
Evaluating Sand Screen Performance Using Improved Sand Retention Test and Numerical Modelling
Authors: Wu B. , Choi S. K. , Feng Y. , Denke R. , Barton T. , Wong C. Y. , Boulanger J. , Yang W. , Lim S. , Zamberi M. , Shaffee S. , Jadid M. B. , Johar Z. , Madon B. B. 
Published: March 2016

Abstract
Sand retention tests have often been used to select optimal screen aperture for standalone sand screen applications. The purpose is to select a sand screen that maximizes hydrocarbon production and minimizes sand production. There are two types of sand retention tests currently used in the industry, i.e., slurry and prepack sand retention tests. The former aims to simulate gradual sand production condition with an open annulus between the sandface and the screen, and the latter to simulate the condition where no such annulus exists. There are, however, no agreed industry standards on how sand retention tests should be performed and test results interpreted.
This paper presents a combined experimental and numerical modelling study on sand screen performance. The objective is to develop an improved methodology for optimal sand screen aperture selection by addressing some of the limitations presented in the existing sand retention tests. A new sand retention test facility has been developed at CSIRO, incorporating a number of improvements into the design and experimental procedure. A key component of the improvements is the ability to separately measure retained screen permeability and sand pack permeability. Correlations have been developed between sand screen performance and key parameters of the sands and screen based on a large number of sand slurry retention tests. Furthermore, the sand retention process was simulated numerically using a 3D fully coupled Discrete Element (DEM) – Computational Fluid Dynamics (CFD) model. Parametric studies have been conducted to assess screen performance and to gain a better understanding of sand retention and production mechanisms.
Sub-Surface Safety Valve (SSSV) Erosion Assessment in HPHT Gas Field - A Case Study
Authors: Toldo Benni , Shuttleworth Andrew , Zabelina Polina 
Published: March 2016

Abstract
The objective of this paper is to discuss a methodology used to assess the erosion risk of well equipment in an HPHT gas field offshore Egypt. Raven is an offshore subsea HPHT wet gas field located in the West Nile Delta region. During the well design phase a few challenges were faced with the erosion assessment of the Sub-Surface Safety Valve (SSSV).
A preliminary erosion study assuming dry gas with no liquids in the tubing showed excessive erosion rates and the potential outcome of having to choke back production. The analysis was performed using different erosion models and empirical formulas and all gave comparable results.
In high rate gas wells the worst case for erosion is in dry gas conditions due to the direct impingement of the produced solids particles with the metal, as there is no liquid to provide ‘cushion’ effect. The metal loss is greatly reduced if there is a liquid film present on the internal surface of the completion equipment, effectively dampening the impact energy of the solid particles with the metal. Produced formation water can help mitigate the erosion rate however it is anticipated that it will be produced only late in field life. The worst case for erosion is experienced at the end-of-plateau conditions, years before water breakthrough.
The next step of the study was then to estimate the amount of condensate dropout in the tubing as a mean of controlling the metal loss. The relatively low expected Condensate Gas Ratio (CGR) of the reservoir fluid implied that the predominant flow regime within the tubing would either be mist or annular flow, but to determine the rate of metal loss it was necessary to quantify the relative velocities of the liquid and gas phases. A black oil retrograde condensate PVT model was generated from a tuned Equation of State (EoS) model and was used in a nodal analysis tool to estimate liquid dropout across the tubing length. The erosion assessment was re-evaluated this time considering the liquid dropout at the SSSV (process conditions) showing an acceptable erosion rate.
This approach can be applied on many high rate gas fields where erosion rate is a threat that could impact the production rates. In our case, demonstrating the presence and quantifying the amount of liquid film in the tubing and the positive effect on reducing erosion, helped define appropriate operating envelopes to deliver the required well potentials.