bluuebunny/crossref_metadata_2025_split huggingface dataset:
Increasing Quality in QHSE Work Processes by Introdusing a Common Platform for the Industry
Authors: Holst Jens Christian , Snøtun Håkon , Mathisen Petter 
Published: March 2016

Abstract

Objective
Safety first has been a slogan for many operators and services companies for a long time, but how is the industry making sure that this leads to actual improvement? Many accident investigations at different levels have revealed that there is a lack of common taxonomy, standardized work processes within and across companies and openness for external audits. We want to point out the areas where we believe that the Oil and Gas industry could learn from other industries, such as car manufacturing as well as the IT industry.
Our work has initially been focused on literature studies and interviews with companies and organizations on the NCS. We have looked at license owners, operators and service companies as well as the authorities, and how they all have been practicing QHSE measurements, improvement, including communication between all involved parties. In the process our aim was to find what system would ideally help a company, independent of size and business area to both capture, follow up and learn from incidents without being dependant on constraints such as the human error factor or large bureaucratic systems.
Throughout our work it has become evident that there are several ways to capture and share experience and incidents between the different companies and systems. We have found that even on a company level there are internal variations in the way this information is gathered. As information is not gathered in a uniform way, analyzing and reporting the data will be a challenge. As we have found that there is no common taxonomy, no standard reporting or standards related to follow-up actions, we anticipate that there will be a large variation in the quality of this. As several organizations are working together on different projects, their different systems are united and expected to communicate. We believe that the high difference in systems and processes makes this impossible and that the solution to is to generate a common tool to address these issues.
How can we based on our findings say that as an industry, we are prioritizing"Safety first"? Why is each and every company developing separate systems and processes, and why is the focus not on quality and simplicatrion. For the petroleum industry to further develop on the NCS, we believe that it needs to learn from other industries work on a common platform where the aim must be to improve, not just to make reports and statistics.
Cuttings Transport Modeling - Part 1: Specification of Benchmark Parameters with a Norwegian Continental Shelf Perspective
Authors: Busch A. , Islam A. , Martins D. , Iversen F. P. , Khatibi M. , Johansen S. T. , Time R. W. , Meese E. A. 
Published: March 2016

Abstract
In oil and gas drilling, cuttings transport related problems are a major contributor to well downtime and costs. As a result, solutions to these problems have been extensively researched over the years, both experimentally and through simulation. Numerous review articles exist, summarizing not only the research history but also the qualitative effect of individual case parameters such as e.g. pump flow rate, pipe rotation, rate of penetration on cuttings transport. However, comparing different studies is challenging, as there is no common reference basis defined in the form of typical and representative set of case parameters.
In order to develop relevant and accurate cutting transport models, it is critical that both experiments and models are targeting flow cases, which are relevant for respective drilling operations. By developing a clear understanding of the industrial parameter space, as well as establishing critical benchmarks, the development of models and corresponding laboratory experiments will become much easier.
Other industries have established such benchmarks (e.g. the "NREL offshore 5-MW baseline wind turbine" in wind power research), providing a standardized set of case parameters and profiles, readily available for use to researchers worldwide and resulting in straightforward benchmark and validation as well as faster project set-up and definition.
For application to modeling of cuttings transport phenomena, we propose a methodology how to derive a well-defined and standardized set of geometrical, operational, and environmental case parameters describing various working points of actual drilling operations and procedures as well as simplified problems. The relevance and application of standard parameters is briefly discussed in the light of modeling, both experimentally and through simulations.
Expandable Liner Hanger Technology Provides Metal-to-Metal Sealing and Improved Anchoring Solution for ERD Wells: Case History in North Sea
Authors: Stautzenberger Arthur , Baird Stuart , Lundgård Geir 
Published: March 2016

Abstract
Extended reach drilling (ERD) wells provide challenges in achieving successful liner hanger installations and liner cement jobs. This paper reviews successful expandable liner hanger (ELH) installations in challenging ERD wells in offshore North Sea and discusses how the metal-to-metal sealing ELH provides a solution to these challenges.
The paper discusses the advantages of the new ELH design, which adds metal-to-metal sealing technology to the existing proven elastomer-sealing technology. In addition, the new design offers improved ELH anchor capability. The paper also describes how the new features of this ELH design provide consistent results to meet the challenges of ERD wells. The paper also examines case histories of four metal-to-metal sealing ELHs set successfully in ERD wells in the North Sea since May 2015.
The metal-to-metal sealing technology of the new ELH design (Fig. 1) provides gas-tight sealing at high and low temperatures, and the existing elastomer seals provide field-proven, gas-tight sealing capability in a wide range of applications. The improved ELH anchor design increases the anchoring capability of the hanger allowing operators to run extremely long liners and meet the demands of ERD wells. Another critical advantage of the ELH is the ability to reciprocate and rotate while running in hole and during the entire cement job preventing bridging and packoffs and providing a quality cement job. These case histories provide evidence the sealing and anchoring technologies combined with the reciprocation capabilities of ELH are critical to successful cemented liner hanger jobs in ERD wells.
This paper presents technical information to increase industry awareness of an additional ELH technology. Because ERD wells are becoming more prevalent, solutions are needed that provide improved reliability, increased operational capabilities, and the ability to provide a quality cement job in a challenging application. The metal-to-metal ELH provides the industry with additional technologies to meet these requirements to successfully drill extended-reach wells.
Enhanced Oil Recovery On Troll Field By Implementing Autonomous Inflow Control Device
Authors: Halvorsen Martin , Madsen Martin , Vikøren Mo Mathias , Isma Mohd Ismail , Green Annabel 
Published: March 2016

Abstract
The implementation of autonomous inflow control device (AICD) has been a success at the Troll field with the objective to limit gas production for long horizontal wells in a thin oil column reservoir. First installed in 2008, recently the AICD was adopted as part of the standard lower completion solution at Troll. To date more than 30 wells have been completed with AICD, demonstrating significant increase in cumulative oil production.
Troll is a large subsea development offshore Norway which started oil production in 1995. Troll multilateral horizontal wells are drilled with total reservoir length typically 3 to 5 km within the thin oil column. Production has been aided by inflow control devices to ensure contribution from all reservoir sections and limit gas production by postponing gas breakthrough and choking gas production after breakthrough.
The Autonomous Inflow Control Device (AICD) provides the same functionality as a passive ICD in that it helps to create a more even inflow along the horizontal section prior to gas breakthrough, but also has a self-regulating adjustable design to provide greater production choking where gas breakthrough occurs. This chokes production from compartments producing large amounts of gas leading to greater oil recovery and lower gas production.
To evaluate the performance of the AICD a comprehensive multi-phase flow model of the autonomous performance has been developed and workflow created for simulation of performance within the reservoir.
This paper will describe the advances in the technology since the first field installation in 2008, and the development and challenges of performance prediction and assessment.
Innovation of Annular Sealants During the Past Decades and Their Direct Relationship with On/Offshore Wellbore Economics
Authors: Jimenez Walmy Cuello , Urdaneta Javier A. , Pang Xueyu , Garzon Juan R. , Nucci Gino , Arias Henry 
Published: March 2016

Abstract
Annular sealants are used as static barriers to avoid fluid communication in-between zones and provide proper isolation of the different formations as well as support and protection to the casing. Therefore, the sealant can have a direct relationship to wellbore integrity. Data suggest more than 4 million hydrocarbon wells have been drilled globally; interestingly, some datasets indicate well integrity failure is highly variable (1.9 to 75%).
Historically, sealants have been characterized for short-term placement properties up to the point at which the sealant is pressure tested and a log is performed to establish if the annulus is properly sealed. However, as hydrocarbon resources are becoming gradually depleted in easy-to-recover environments, harsher conditions are more common. Additionally, stimulation and enhanced oil recovery (EOR) techniques involving high-pressure and high-temperature (HP/HT) cycles during the entire well life pose significant challenges to the sealant's integrity.
Sealant integrity issues can result in very high remediation costs, reduction of hydrocarbon production, and in some cases, loss of the well. All of these can lead to an increased cost per barrel of oil equivalent (BOE). During the last few decades, in view of the drastic changes in drilling conditions toward more challenging environments, the industry has opted for a sealant design approach, which considers all of the events that occur throughout the entire life of the well and their effects on integrity of the sealant and wellbore. This approach can be successful by employing analytical tools, which allow for synchronizing all of the different events and/or operations occurring during wellbore construction (from drilling to abandonment) with the different elements that encompass the wellbore architecture (geometry, formations, casing, and sealant). The use of these tools' forecasting capabilities can result in data-led decisions that allow operators to construct wellbores more efficiently and with more confidence, which should ultimately help reduce production costs.
This study focuses on illustrating an analytical tool for predicting the sealant's performance in both onshore and offshore cases throughout the life of the well and determining how this affects wellbore economics in the long term. Moreover, this paper discusses how sealants have evolved from conventional Portland cements to elastic-, foamed-, glass-bead-extended cements, and epoxy-resins based on wellbore integrity predictions performed by analytical tools. The impact of nanomaterials in converting cement/sealant systems into multifunctional and/or smart materials capable of self-sensing specific stimuli (i.e. stress, strain, etc.) is also shown.
Economical Slot Recovery Using Open Hole Cement Plug Kick Offs, a Proven Success in North Sea
Authors: Hussain Sajjad , Dhaher Karam Sulaiman , Bjoerneli Hans Magnus , Noekland Magnar , Blackburn Jason , Monsen Gisle Otto , Haaland Sigurd , Hongdul Thanong 
Published: March 2016

Abstract
In recent years, slot recovery to drill more wells in brownfields has posed different challenges due to extensive and time consuming Plug and abandonment (P&A) and casing cut and pull operations [SPE 173954].
In 2013, For the first time on Statfjord Field, a ruggedized point the bit rotary steerable system (RSS) and Gyro while drilling (GWD) were used to sidetrack off cement plug in 17 ½-in hole section through a narrow window (80m) between 20-in casing shoe and 13 3/8-in casing stump. This reduced risk and saved time by sidetracking and drilling the section in one run. In similar scenarios on previous wells, mud motors had been used to kickoff and sidetrack from a cement plug between the casing shoe and casing stump. Two runs were always required to complete the sections; first run with a dedicated sidetracking assembly (motor BHA) and a second run with a drilling assembly (RSS BHA). After this success another attempt was made in 2014 where 17 ½-in section was sidetracked and drilled to TD through 40m narrow window between 20-in casing shoe and 13 3/8-in casing stump in high well collision risk environment. Significant time and cost saving was achieved on this project. In 2015 a challenging well was planned where kick off had to be done through 37m window and close to six producers. Due to high risk of collision and no possible option of whipstock exit, new Point the bit RSS technology was employed to kick off in high magnetic interference environment and drill the section in one run.
With the ruggedized point the bit RSS and GWD service, it was possible to constantly monitor direction and inclination in real time and thereby tracking the trajectory progress in the loose formations at shallow depth. This allowed to guard against dropping back to the mother bore and hitting the 13 3/8-in casing stump. Sidetracking in open hole from cement plug also increased formation strength at 20-in casing shoe and saved time/cost compared to whipstock exit.
During execution all three wells were sidetracked successfully from motherbores in the first attempt and drilled to section TD in one run saving significant rig time and cost.
This paper discusses the planning and execution phases of these three successful reentry wells drilled on Statfjord Field, one of the largest field on North Sea Continental Shelf (NCS).
Mathematical Approach of MSE in Thermo-Poro-Elastic Conditions Improves Decision Making to Use RWD
Authors: Roohi Abbas , Elmgerbi Asad , Nascimento Andreas , Prohaska Michael , Thonhauser Gerhard 
Published: March 2016

Abstract
Historically Reaming While Drilling (RWD) operations have been restricted to softer formations. The objective in this study is to create a thermoporoelastic model of Mechanical Specific Energy (MSE) for RWD in order to shed important new light on the decision process how to use RWD for a specific formation as well as a recommendation for reamer-pilot size ratio.
The analytical approach developed in this paper calculates thermoporoelastic coupled time-dependent stress, pore pressure and temperature variations for an inclined borehole that is drilled through permeable or impermeable formation and which is subjected to far field three dimensional in-situ stresses. Apparent rock strength of the rock in Depth of Cut (DOC) zone beneath the reamer can be determined by using Mohr-Coulomb theory. By using Apparent Rock Strength (ARS) the analytical Mechanical Specific Energy (MSE) can be estimated afterwards. This parameter can be used as a key decision to determine whether a specific formation is a good candidate for RWD or not.
A proper combination of pilot and reamer is absolutely critical to optimize bottom hole assembly (BHA) performance and durability. For many years, a trial-and-error technique has been employed by the drilling industry to determine advantages or drawbacks of reamer in the BHA and the optimum reamer-to-pilot-size ratio and bit characteristic for drilling, which requires a significant investment of time and money.
The comparison of reamer's MSE, to destroy rock around the wellbore, with bit's MSE, to destroy rock at the bottom of the hole, shows how efficiently reamer can drill rock around the wellbore in certain formation, and in some other formations the drawbacks are outweigh of its advantages. This in turn makes it possible to determine proper formation characteristics to employ reamer in the BHA and also the maximum reamer/bit size ratio for certain rock characteristics in order to support efficient drilling operations.
Considering that so fare in the market there is no evidence of a specific model to predict rock strength bellow the reamers, this research and study show its degree of novelty since it propose a model to fill this gap, which can in the future and after tuning be used as a reference application in the petroleum industry for decision making and project cost analysis. Validation in different environments is still to be concluded as a next step in this research.
Nanoscale Morphology of Brine-Oil-Mineral Contacts in Connected Pores of Carbonate Reservoirs: Insights on Wettability from Cryo-BIB-SEM
Authors: Schmatz Joyce , Klaver Jop , Jiang Mingze , Urai Janos L. 
Published: March 2016

Abstract
We used Broad Ion Beam slope-cutting in combination with Scanning Electron Microscopy undertaken under cryogenic conditions (Cryo-BIB-SEM) to study mineral-oil-brine contacts in reservoir carbonates. This direct imaging method allows pore scale investigation of in-situ fluids and their distributions down to the nanometer scale.
In this study we compare two types of carbonate reservoirs: a fine-grained Lixhe limestone (Belgium) and a coarse grained limestone from the Maastricht area (Netherlands). In both samples we first quantify the porosity using BIB-SEM and derive the spatially resolved pore connectivity of the rock from BIB-SEM on Wood's Metal (WM) injected sub-samples. In the second step sub-samples were saturated with the oil analogue n-hexadecane and NaCl-brine.
Cryo-BIB-SEM in combination with high resolution EDS imaging and automated image analysis on the saturated samples allowed for a quantification of the oil droplet size, the lengths of oil-carbonate contacts and the 2D contact angle of carbonate with brine and oil. Our results show that these features (e.g., contact line length, contact angles, effect of surface roughness) are present on the scale of a few tens of nanometers to a few micrometers, which is in agreement with numerous theoretical and experimental studies. Hence, this technique permits the testing of predictions on the morphology and dynamics of contact lines in relation the mineral properties, which is not possible with other imaging methods, such as X-Ray Micro Computed Tomography (µ-CT), due to limits in resolution. Our results call for improvements in models of multiphase pore-scale flow in digital rocks.
Determining Optimum Aging Time Using Novel Core Flooding Equipment
Authors: Ahkami Mehrdad , Chakravarty Krishna Hara , Xiarchos Ioannis , Thomsen Kaj , Fosbøl Philip Loldrup 
Published: March 2016

Abstract
New methods for enhanced oil recovery are typically developed using core flooding techniques. Establishing reservoir conditions is essential before the experimental campaign commences. The realistic oil-rock wettability can be obtained through optimum aging of the core. Aging time is affected by temperature, crude oil, formation brine, and coreplug lithology. Minimum time can significantly reduce the experimental cost while insufficient aging time can result in false conclusions.
Real-time online resistivity measurements of coreplugs are presented and a novel method is introduced for determining the optimum aging time regardless of variations in crude oil, rock, and brine properties. State of the art core flooding equipment has been developed that can be used for consistently determining the resistivity of the coreplug during aging and waterflooding using advanced data acquisition software. In the proposed equipment, independent axial and sleeve pressure can be applied to mimic stresses at reservoir conditions. 10 coreplugs (four sandstones and six chalk samples) from the North Sea have been aged for more than 408 days in total and more than 29000 resistivity data points have been measured to consistently investigate the change of wettability during aging.
At 60°C and 100 bars a homogeneous sandstone coreplug attained optimized wettability after 5 days, a heterogeneous coreplug required 30 days of aging. Chalk coreplugs needed 45 days of aging. This shows that coreplugs originating from the same field, when aged at equivalent conditions can have significantly different aging times because of minor variations in the coreplug properties. No fixed aging time can be recommended on the other hand a method is recommended which can determine the extent of aging. Coreplug aging patterns were studied for variation in pressure (20 to 130 bar) and temperature (60 to 130°C). Based on these experiments an algorithm has been developed which distinguishes the effect of wettability alteration, pressure, and temperature on coreplug resistivity.
This study highlights the use of hydraulic oil to avoid release of fluids in the effluent pipes during the aging process. Furthermore, the described multiple monitoring devices are useful in detecting any experimental error that may have occurred during mounting of the coreplug in the core holder. Thus imperfect waterflooding which can otherwise produce misleading data can be avoided.
The presented equipment can instantly and continuously calculate the mineral wettability throughout the aging process at any pressure, temperature condition and for any combination of rock and crude oil. Thus, using the stated core flooding equipment can not only decrease the cost and time of doing aging and waterflooding studies but can also significantly increase the accuracy in conducting core flooding experiments.
Solutions to the Curve Fitting Problem of Mathematical Correlation and SCAL Data
Authors: Arief I. H. , Xue Lili , Lomeland F. 
Published: March 2016

Abstract
Mathematical correlation has been widely used in oil and gas industry to model relative permeability and capillary pressure from water saturation. The application of mathematical correlation is essential especially in the absence of laboratory data. Additionally, the correlation is also applied to generate a refined relative permeability and capillary pressure table as the input to reservoir simulation.
There are several correlations being used in the industry such as Corey, Skjæveland and LET correlation. The focus in this paper is the LET correlation. The correlation offers more flexibility as well as accuracy in matching the responses from laboratory experiments.
Having a representative correlation is the basic, but the curve-fitting to the experimental data is also indispensable. In a problem which involves a non-linear correlation, the attempt to find a solution which fits the experimental data becomes more complex. To overcome this problem, it is fundamental to have a search method which can fit the experiment data with the lowest possible residual errors.
In this paper, different search methods of curve-fitting are investigated. In the last part of the paper we will compare the performance of each method. The main evaluation parameters are the residual error and the computational time. The methods studied in this paper are the Levenberg – Marquardt method, particle swarm optimization and mesh pattern search.