bluuebunny/crossref_metadata_2025 huggingface dataset:
Integrated Techniques for Continuous Rocks Elastic Properties Profile and Geomechanical Characterization
Authors: Hussain Maaruf , Amao Abduljamiu , Muqtadir Arqam , Al-Ramadan Khalid , Babalola Lamidi , Jin Guodong
Published: November 2019

The knowledge of rocks elastic properties (REP) is crucial to geomechanical modeling throughout an asset life cycle. Reliable geomechanical models requires calibration of well log REP with core measurements. However, sample availability, representativeness, time, and cost are problems associated with core measurements. In this paper, we integrated REP derived from two laboratory techniques performed on several core covering over 800 ft interval samples from Paleozoic tight sands and shale reservoirs to obtain a continuous REP profile for better- upscaling of reservoir model parameters. For lithology delineation, intact core samples were scanned utilizing MicroXRF. While, REP was measured using Autoscan and AutoLab systems. The Autoscan employs non- destructive technique to characterize the variability of REP. The AutoLab uses the standard triaxial testing method to provide REP at reservoir conditions. The results were tabulated and statistically treated to establish significant empirical relationships. REP derived from triaxial tests on selected samples include, the P and S wave velocities (Vp and Vs), static moduli (Young’s modulus (Es) and Poisson’s ratio (vs)), as well as dynamic moduli (Young’s modulus (Ed) and Poisson’s ratio (vd)). While the reduced Young’s modulus (E*) was obtained from non- destructive method. Lithofacies were established from elemental data. The E* reveals details of several geomechanical heterogeneity and anisotropy which are not possible with traditional triaxial method. There is a significant correlation between E* and Es, Ed, Vs, and Vp. A continuous REP profile was developed using E* with geochemical data. Based on the characterized profile, fracture height growth barriers identified were toughness/modulus and interface barriers. These can significantly affect hydraulic fracture vertical growth within the studied Paleozoic tight sands and shale reservoirs units.

The approach, which uniquely considered scales of rock geochemical and mechanical properties and data analytics, demostrate the possibility of generating a continuous REP profile using laboratory aquired dataset. Thus, the difficulty associated with geomechanical characterization and model calibration of highly laminated unconventional reservoirs using actual laboratory data is resolved. This has a directly implication to both conventional and unconventional geomechanical modeling, where the determination of upscaled-reservoir model parameters matters.
Condition Monitoring, Continuous Condition Monitoring or Predictive Maintenance? That’s the Question!
Authors: Ferket Johan
Published: November 2019

Asset-intensive companies face tighter maintenance budgets, stricter regulations and increased pressure to improve asset performance, whilst confronted with aging assets and workforce. Managing an asset with these challenges requires informed decision-making based on insight, knowledge and forecasting. Data is a powerful tool to achieve this goal.

‘Internet of things’ innovations have led to a rapid increase in the availability of technical and business data. A few years ago, techniques that were complex and expensive are now more affordable, accessible and increasingly important in order to compete in this world of rapid change.

Field data is faster and immediately available for processing, while more relevant measurements and observations of similar or better quality are leading to more reliable information for decision-making.
Enhancement of Routine Data Acquisition in a Giant Offshore Brownfield by Bridging Gaps Identified Through Comprehensive Data Analysis
Authors: Zhao Wenyang , Al-Neaimi Ahmed Khaleefa , Saif Omar Yousef , Abed Abdalla Abdel
Published: November 2019

Reservoir management is a data driven process with an objective to achieve an optimum ultimate oil recovery. It is fundamental to obtain a proper understanding of well and reservoir performance, which can only be built based on the acquired data. Data acquisition in brownfield has been a significant challenge due to the obsolete control system, accessibility and workflows. Daily well changes is one of the key pieces of data required in routine allocation, well performance analysis, as well as simulation model updates and hence development plans. There are two major types of acquired data in the presented giant offshore brownfield, which are manually measured by operators and automatically recorded data through available SCADA system. A comprehensive data analysis has been conducted based on historical production data and reservoir surveillance data to spot the gaps and identify the opportunities for future improvement.

Gaps in daily well changes data have been observed from both manually and automatically acquired data. It has been summarized into two main categories, which are data inaccurate and data missing. The inaccuracies are mainly from improper use of well change event types, inaccurate timing of data acquisition and malfunctioning of SCADA systems. Missing data includes loss of manual measurement records and insufficient utilization of SCADA data. The paper presents real examples of all these findings and a proposed workflow to enhance the data acquisition process. The concise and explicit workflow is one of the most efficient approach to tackle the hardware and manpower limitations. The importance of daily production events could not be over emphasized. Specific actions to bridge the identified gaps are crucial to achieve a sound reservoir management, maintain the sustainability, and ensure an optimum oil recovery.
Mitigate H2S Spike in 4A Molecular Sieve Gas Dehydration
Authors: Sreenivasan Venkatesh , Alladwar Santosh Govindrao , Noakes Kim
Published: November 2019

Dealing with wet sour natural gas is a global challenge faced in many plants worldwide and dehydration units are to be optimized to reduce the overall project cost. Normally 3A molecular sieve is preferred in sour gas dehydration applications as it does not adsorb H2S. The design illustrated in this paper depicts an innovative method for designing sour gas dehydration units using 4A molecular sieve that can mitigate H2S spike, reduce molecular sieve unit capital cost and operating cost of regeneration system by use of variable adsorption cycle.

The variable adsorption cycle increases water loading in beds by maximizing adsorption time to desorb H2S molecules and thereby mitigate H2S spike during regeneration. This also prolongs mole sieve bed life by reducing the number of bed regeneration cycles as compared to fixed adsorption cycle. This design can be used in gas dehydration units downstream of acid gas removal units.

This paper also proposes to avoid mixing of regeneration gas with main feed gas of mole sieve bed and instead propose to treat the regeneration gas at upstream acid gas removal unit to accommodate the H2S spike.
First Successful Innovative Approach of Pad Drilling Implementation in a Brown Onshore Oil Field in the United Arab Emirates
Authors: Quintero Fernando , Ahmad Hussain Mushtaq , Al Reyami Mazin , Al Nuaimi Mouza Ali , Al Dhanhani Omar Ahmed , Pham Dang Le Khoa , Abdulmohsen Abed Mohammed Al Yafie Mohammed
Published: November 2019

Pad Drilling Concept was developed to increase and sustain the production rate one of the UAE Brownfield Onshore Oilfield (BO) from four different reservoirs. The surface facilities of the field will accommodate total of 80Mbd and technical rate of 96Mbd.

The project scope was redefined in 2016 to enhance the overall project's cost and further study on newly developed reservoir (Reservoir "A"). The project came into execution since January 2018 and so far, 100 plus wells drilled successfully. Therefore, to accommodate the required number of wells based on the company production target ahead of time, the planning stage represented as per 2018-2022 business plan is maintained with first oil in Q1 2020.

The Full Field Development Plan (FFDP) is to deliver a total of 210 wells to sustain the production rate beyond 2024. Thus, the selected scheme for the FFDP which is planned to be artificially lifted is based on water injection and water alternating gas injection (WAG).

The Key aspects of the project are:Partial development of Reservoir "A"Sensitive environmental areaBrownfield development in Simultaneous Operations (SIMOPS) conditions.Directional Drilling trajectory and anticollision constrains.

Critical success factors for this project are:Integrated Project Management Team with dedicated full time resourcesAppointment and selection of competent Engineering contractor to develop the facilities within the target time.Timely approval and implementation of project's milestone.

Thus, the benefits from the project for this Field are:Optimized Field Development Plan;Prevent congestions & access constraints;Standardization of HSE & Operations;Economical Surface Facilities Management.Rig days and cost saving.Sweep Efficiency of the reservoir.Early completion / production of project.
New PDO Improved Well Design 15K Cemented Completion to Successfully Deliver Faster and Cheaper Complex Deep Gas HPHT Wells
Authors: Al Naabi Hashil Nasser , Al Hinai Al Mukhtar , Al Adawi Anwar Said , Al Kiyumi Hassan Ali , Al Aghbari Mohammed Ali , Al Abri Mohammed Thabit , Al Suleimani Ibrahim Hamed , Al Busaidi Naser Mohammed , Al Humaimi Mahmood Ahmed , Youssef Hamada Abdelhameid
Published: November 2019

This paper discusses the continuous improvement in Khulud field, the most challenging field in Sultanate of Oman in terms of high pressure and high temperature. A paper (SPE-188629-MS) was published in 2017 under the title of " Achieving a Step Change in Well Duration and Cost in a HPHT Tight Gas Field" which explained many improvements in different areas including (10k cemented completion and degraded mud, operational optimization and efficiency, slim design). However, in this paper, the focus will be on 15k cemented completion, which was a challenge in that time for both designs (fat and slim). Thus, the new improvement is mainly in well design, which led to significant reduction in well delivery cost and time for 15k wells.

Drilling and completing very tight HPHT deep Gas well can be very challenging. The risk of losing the well is real due to challenges related to liner hanger system failures that have been experienced several times within the field. In addition, stuck pipe risk of cleanout assembly prior to running liner top completion is another serious challenge that had led to abandoning a few wells in the past.

Cemented completion for 15K well is one of the challenges mentioned in the SPE-188629-MS paper in Khulud field. Production casing is not strong enough to handle hot kill load in case completion tubing leaks and as well is not designed for full gas displacement. In addition, many failures were encountered with liner hanger system, which compromises well delivery in some cases. To overcome such challenges and reduce well delivery time and cost, PDO initiated new well designs to cater for 15k cemented completion for both fat and slim applications. Advantages and disadvantages of cemented completion for both designs will be discussed in this paper.

In fat design, production casing was upgraded to higher weight and grade. 7 in casing was eliminated as the new production casing is good enough to handle hot kill load in case tubing leak happens.

In slim design, ECD and high surface pressure are the main concerns. The team managed to simulate, optimize ECD for different scenarios and mitigate high surface pressure. All Risks and associated consequences were captured. A mitigation plan was developed. Future improved design has been evaluated but not approved yet which will drive cost reduction and operational efficiency.
The Application of a Fiberglass Liner in Well Tubing as Cost Effective Material Option in High Velocity Production Wells
Authors: Repetto Carmen , Gorini Simone , Nutricato Giacomo Andrea , Torri Lucia , Cavassi Paolo , Zucchetto Maria Ornella , Guglielmo Carmelo , Gravante Elpidio , McIntosh Neil , Balistrieri Roberto
Published: November 2019

The composite liner is made of a Glassfibre Reinforced Epoxy (GRE) resin, inserted in Carbon Steel tubing and it can be used in both production and water injection wells.

Different laboratory tests performed either by manufacturers and by operators, have been carried out in order to confirm and verify the material characteristics and reliability.

In particular, Eni in 2009 tested GRE in sour environment with CO2 and H2S to investigate the capability and service limits of the resin liner at different temperatures.

According to the positive results of the tests, Eni has firstly applied GRE in 2005 in Tunisia where it was successful in reducing onshore workover costs and extending the life of Carbon Steel tubing in oil producer wells with high CO2 and water cut.

The latest application was in Norway where it has been installed on water injector offshore wells, where, due to high corrosiveness of the injection fluid (raw seawater with antifouling chlorination), the liner was selected as cost effective alternative to high alloyed materials.

More recently, Eni was involved in particularly challenging deepwater development projects with highly productive gas wells in sour and harsh environment.

Typically, these applications require high grade Corrosion Resistant Alloys (CRA) production tubing with an important impact on the completion costs and operative run in hole issues. Following the positive experiences gained in the last 15 years in the application of glassfibre liner, it was evaluated the possibility to deploy the material as a corrosion barrier in well production tubings under more critical conditions.

Eni decided to perform some additional laboratory tests in collaboration with Milan Polytechnic. Direct impact test and straight pipe test were performed in order to characterize the erosion behaviour of GRE composite material, supplied by two different manufacturers, and simulating the case of wells with high erosion rate risk.

The results demonstrated GRE to have a good resistance to the solid particles erosion in comparison to very similar tests on Inconel Nickel Alloy material and confirmed the potential use of GRE as a corrosion resistance material when combined with Carbon Steel tubulars as an alternative to the usual high CRA materials in producer wells.

This paper will present the characteristics of the technology, the laboratory tests performed with their results and the acceptable range of field conditions.

Additionally, the paper will provide Eni field experiences, including feedback, lessons learned and economic evaluations.
Integrated Reservoir Modelling using Spatio-Temporal Unsupervised Learning and Integrated Visualization
Authors: Simha Srungeer , Tummala Pradeep , Kumar Viren , Singhal Manu , Viswanathan Michelle , Kawar Raed , Dijk Harm
Published: November 2019

Probabilistic modelling is one of the most frequently used methods in reservoir simulation to manage uncertainties and assess their impact on reservoir behavior/cumulative production. However, depending on the extent of the uncertainty, 100s of scenarios can be generated leaving engineers unable to meaningfully analyze this data. To remedy this an unsupervised machine learning based workflow was developed to identify unique scenarios which was then paired with an integrated dashboard to enable rapid and deep analysis.

A case study was done using data from a Shell operated gas field in the North Sea. Data was first mined from 480 history matched scenarios using python; out of which 20 unique clusters were identified through K-Means clustering of pressure and saturation changes with time in each gridblock. This meant that the team had to look only at 20 scenarios instead of 480 to understand the effect of different inputs on pressure and saturation response. For enhanced analysis, an integrated visualisation dashboard was created to visualize pressure and saturation changes, production profiles and connect them back to input parameters

The new methodology enabled the team to integrate different aspects of reservoir modelling from static to dynamic to surface constraints on a single dashboard, making it possible to find patterns in large volumes of data which was previously not possible. For example, a cluster was identified which had high water movement; upon inspection of input parameters it was seen that late life recovery was significantly different in this cluster as compared to others. Being able to visualize different properties of multiple scenarios simultaneously at both group and grid level is a very powerful tool that not only generates insights but significantly reduces analysis time and helps in quality checking property modelling and grid behavior.

The developed workflow is quite generic in nature, capable of working with various simulators and can be extended to assessing history match quality in Assisted History Matching (AHM) and multi-scenario modelling. Key parameters impacting different scenarios were identified and the team observed 10x reduction in time and significant reduction in manpower requirements through the new approach
Fully Integrated Modelling of Subsurface, Remote Sensing and Outcrop Geology; Prospect Generation in the Paleozoic of the Ahnet Basin Algeria
Authors: van Dijk Janpieter , Guney Hasan
Published: November 2019

The fully integrated modelling of subsurface seismic and well data with outcropping surface geological data is a challenge in which the application of modern technologies which involves the standardisation of datasets on different scales and from different sources plays a key role. In this paper we present an example of the Paleozoic of the Ahnet Basin in Algeria where a prospect generation exercise was undertaken integrating data from 2d and 3d seismic volumes, logs and core data from previously drilled wells, maps of outcropping geology, and high-resolution remote sensing datasets.

The geology of the area is well known from previous studies on both surface geology and well data, and comprises a Paleozoic series unconformably resting on infra-Cambrian relative basement, and made up of clastic sedimentary series with intercalation of limestone sediments ranging from Cambrian to Devonian Age, which comprise various gas bearing tight reservoirs some of which producing in this part of the Basin. These are present in anticlinal structures of Hercynian Age which are partly eroded and covered by Cretaceous bioclastic limestones. The anticlines show a deformational history reflecting an interference of differently oriented Hercynian transpressional deformation patterns overprinted by later stage, Alpine reactivations. Our integrated geological analyses permitted to propose a new updated view on the geological history of the area. This includes the reconstruction of the structural deformation of the Hercynian anticlines, and the reconstruction of the post-Hercynian geological evolution including structural reactivation, showing tilting and upheaval of the area in Alpine and Recent times.

An extensive interpretation of outcropping geological structures was performed using high resolution satellite images and specific image processing. This was calibrated with available high-quality geological maps and some later additional limited geological surveys. Detailed well log correlations and seismic interpretation 2d and 3d seismic data provided a detailed framework of subsurface structures. The datasets on surface vand subsurface originally coming from different digital sources were integrated in one uniform interpretation environment using best practice standardization which permitted to drive the seismic interpretation and depth modelling, by carefully calibration with outcropping features such as bedding dip, fault trends and fold axis trends. Applying regional velocity modelling this permitted to correctly map the geological structures and prospects in the area, and perform an articulated exercise of Prospective and Contingent Resources estimates.

The application of an integrated geoscientific workflow deploying up-to-date technologies which integrate GIS with a surface-subsurface 3d modelling space shows the validity of new developments of the 4th Industrial Revolution in the planning of E&P Prospect evaluation.
Application of New Generation Transformer Harmonic Filter Hybrid Solution
Authors: Orlowski Thomas , Jasinski Leszek
Published: November 2019

In recent years, Electrical Submersible Pump operators are facing increasing demands to provide more economical ways of producing crude oil at the well site. One of the ways to decrease the cost of production is to reduce the cost of electrical energy used for the ESP system. The limiting of harmonics produced by ESP electrical systems to IEEE-519 recommended levels is widely used, yet greatly misunderstood, as there are a variety of methods and tools that must be made compatible with the application in order to achieve successful mitigation of the harmonics.

Increased horsepower, larger electrical ESP systems, and greater energy consumption require more space at the well site. On offshore installations, that space has always been at a premium. The footprint expansion of this ESP electrical equipment would create unacceptable costs considering the current cost-saving market conditions.

This paper presents an innovative approach to tackle harmonics mitigation. This significantly smaller and cheaper approach delivers the required IEEE-519 THDI in ESP electrical system whilst incorporating new technologies that present characteristics capable of increasing the run life of an ESP electrical system.

A typical ESP electrical system installation has usually contained the following: SDT – Step Down Transformer, HF – Harmonic Filter [or some other means of controlling harmonics], VSD- Variable Speed drive, SWF – Sine Wave Filter, SUT – Step Up Transformer, and ESP Motor. Combining the Step Down Transformer with the Harmonic Filter and designing it as a one-piece unit, cooled in oil, creates a smaller and therefore more cost-effective device, that achieves more desirable harmonics characteristics. Including not only efficient cooling, but the use of parasitic inductances of transformer windings as a useful component of the integrated harmonic filter gives an advantage on the technical market. This paper provides further discussion and details on this concept's advantages as a solution to reducing operating costs.
Competency Assessment of HSE Critical Positions
Authors: Al Muhairi Mohammed , Kruger Michael
Published: November 2019

This paper presents Borouge experience in terms of The Competency assessment of critical positions program which has been developed based on best available practice and it will set Borouge competency strategy for Certification and assessment to uplift the performance and excel in HSE and Process Safety programs.

Statement of Theory and Definitions

Borouge strives to be recognized as a leader for delivering the "Best in Class" HSE and Asset Integrity performance. Due to that we have come up some initiatives which is designed to enhance the HSE performance to prevent incidents.

A Benchmarking study has been conducting to have overall look on how to improve Borouge Education and training system by first analyzing our own process, then finding better process among other comparable Processes.

Objective: ✓Identify opportunities to enhance quality, eliminate duplication, and streamline processes✓Collect baseline data✓Clarify desired outcomes

The benchmarking is encompassing the below areas the HSE training and education: HSE training matrixTraining cycleTraining authorization and certificationPerformance measurement / indicatorNon conformity, corrective action and preventive actionRecord keepingthe competence requirements levelOutlines the training priorities;Review/AuditE- learning system
SmartWater Synergy with Surfactant Chemicals: An Electro-Kinetic Study
Authors: Alghamdi Amani , Ayirala Subhash , Alotaibi Mohammed , Alyousef Ali
Published: November 2019

SmartWater flooding through the injection of optimized chemistry water has lately become an attractive proposition for enhanced oil recovery in carbonate reservoirs. The wettability alteration towards water-wet conditions caused by favorable surface charge alteration is identified as the main mechanism responsible for oil recovery.

In this experimental investigation, the impact of SmartWater/surfactant synergy on wettability alteration was thoroughly studied by measuring zeta-potentials at calcite/brine and crude oil/brine interfaces using electrophoresis technique. Different types of surfactants are considered including: anionic, amphoteric and non-ionic. Four different water recipes representing SmartWater (10-times reduced salinity) were chosen at a fixed lower salinity as well as the high salinity water (HSW).

The results showed that both anionic surfactants increased the magnitude of the negative zeta-potentials at the interfaces by almost same order of magnitude. The negative zeta-potentials of calcite and crude oil were increased the most with anionic surfactants in NaCl brine. SmartWater showed relatively higher negative zeta-potentials for calcite when compared to Na2SO4 brine and HSW in the presence of anionic surfactant. These results indicate that both NaCl brine and SmartWater can synergistically combine with anionic surfactants for effective wettability alteration in carbonates. Amphoteric surfactant showed a negligible impact on electrical double layer (EDL) expansion and consequently the wettability alteration. The nonionic surfactant induced electrostatic repulsion forces at both calcite/brine and crude oil/brine interfaces in high salinity seawater and as a result it can be considered as the best chemical formulation to reduce interfacial tension and cause wettability alteration in conventional chemical flooding processes. The negligible impact of adding surfactant chemicals on the measured di-electric constant of different brines confirmed the robustness of zeta-potential values reported in this study.

This work for the first time evaluated the synergistic effects of different brines including the SmartWater with surfactant chemicals by measuring zeta-potentials at calcite/brine and oil/brine interfaces. The optimally suited water recipes were identified to synergistically combine with these chemicals to enhance wettability alteration in carbonates. The new knowledge gained from this electro-kientic study will provide practical guidance on how to design efficient chemical flooding processes for enhanced oil recovery in carbonate reservoirs.
Improving Sulphur Plant Reliability and Efficiency
Authors: Liu Zhenhai , Agung Margono Kuntadi , Kiebert Jan
Published: November 2019

ADNOC LNG on Das Island facility consists of three process trains. Each train contains one Sulphur Recovery Unit (SRU) which comprises a three-stage Claus unit followed by a SUPERCLAUS® unit. In the past 5 years, average Reliability of these SRUs is 85.7%, much below 98% of the LNG group benchmark value. The calculated Sulphur recovery efficiency in Clause mode is between 92% to 96% which is well below the target value of 97.5%. The SRU reliability and efficiency continue to have a negative impact on Sulphur production loss as well as flaring and emissions.

This paper describes corrective actions taken by ADNOC LNG to address these issues in order to improve SRU reliability and efficiency and to minimize production losses and flaring. The implementation of these corrective actions has resulted in 8% improvement on SRU reliability. Sulphur recovery efficiency under Clause mode increased by 3.1%, leading to a significant reduction on flaring and emission, as well as increase on Sulphur production.
Corrosion Resistant Alloy Pipeline Installation for High Pressure High Temperature Requirement
Authors: Kassim Khairan Syuhada
Published: November 2019

This paper discusses on the methods of the installation of Corrosion Resistant Alloy (CRA) pipeline for High Pressure High Temperature (HPHT) including its challenges and the subsequent mitigations.

The experience is based on the successful installation of Anjung Gas Development Project which consists of 18" diameter X 8km length of CRA Full Well Stream (FWS) pipeline installed utilizing the (Dynamic Positioning) DP-2 pipelay vessel. The methodology applied in the installation is via typical S-lay utilizing automatic welding system (for the pipelaying) and stalk-on (for the risers at both sides of the platforms). Additionally, Zero Radius Lay (ZRL) method was utilized at buckle triggers. On the existing KAKG-A platform, the riser installation is via suck-in method to avoid removal and reinstatement of the existing riser guard. Two (2) numbers of anode sleds were utilized for cathodic protection. The scope for pre-commissioning performed was flooding the pipeline with fresh water, cleaning, gauging, hydrotesting, air drying, nitrogen purging and packing.

Multiple Concrete Weight Coating (CWC) thicknesses was used to cater for anchoring of pipeline walking. One (1) set of tensioner shoe pads was moulded to suit all CWC thicknesses in order to mitigate the issue of maintaining two (2) tensioners holding the pipeline during pipelaying. The other two (2) tensioners onboard the Main Work Barge (MWB) were installed with sets of tensioner shoe pads suitable for different thickness of CWC. Although with various weld defects experienced, mitigations that were executed proved that the layrate could be improved and finally achieved the target layrate. A wet buckle procedure including its equipments was prepared as a contingency plan. However, due to no wet or dry buckle, this procedure and equipment were not utilized. The project completed successfully with zero Loss Time Injury (LTI) and no major issues. Hence, it is an achievement for PETRONAS. It sets as a standard in moving forward in any new technologies that is developing.

The overall schedule was improved by approximately 20% and cost was reduced by approximately 15% due to the above mitigations. The impact of the successfulness of this pipeline installation is a basis for PETRONAS future CRA pipeline installation as this is the first HPHT CRA pipeline installed by PETRONAS Carigali Sdn. Bhd. (PCSB). This proves one of PETRONAS' 5 Quality Principles, Right Things Right Every Time. The challenges including the mitigations are a good lesson learnt for any future CRA pipeline installation projects that the industry will be undertaking.

In this project, the PETRONAS Technical Standard (PTS) 193004 Installation of Offshore Pipelines and Risers (Amendments/Supplements to ASME B31.8, ASME 31.4 AND DNV OS F101) and API 5LD is the basis for the installation.
Reservoir-Scale Characterisation and Prediction of Microporous Limestones. Example the Arab Formation Upper Jurassic, Onshore United Arab Emirates.
Authors: Bin Ishaq Wala , Al Darmaki Fatima , Lucas Noel , Al Mansoori Mohamed , Deville De Periere Matthieu , Foote Alexander , Bertouche Meriem , Durlet Christophe
Published: November 2019

In the onshore sector of the United Arab Emirates, the Lower Arab D Member (Kimmeridgian) typically encompasses a thick succession of rather homogeneous low-energy mid-ramp carbonate mudstones interbedded with minor storm-induced cm-scale skeletal-rich floatstones. Within these deposits, the pore volume is dominated by locally abundant matrix-hosted micropores, along with variably abundant open to partially cemented fractures, primary intraparticle macropores and rare moulds and vugs. As a result of this variably developed pore system, measured porosity varies from poor to very good, while permeability changes from extremely poor to rarely good. Detailed petrographic observations (thin-sections, SEM) carried out within six cored wells in a sour gas reservoir highlight that the variations in reservoir properties are primarily linked to the micron-scale variations in the micritic fabric. Indeed, anhedral compact micrites with coalescent intercrystalline contacts are associated with very small and poorly connected micropores, while polyhedral to subrounded micrites with facial to subpunctic intercrystalline contacts show locally well-developed micropores and therefore better reservoir potential. δ18O and δ13C isotope measurements do not discriminate both micritic fabrics, indicating a recrystallisation of the matrix within shallow burial conditions. However, bulk XRF measurements, and especially SiO2, Al2O3 and Fe2O3 content indicate that poorly porous anhedral compact micrite host more insoluble material and have been prone to a greater compaction compared to porous polyhedral micrites. Log-derived elastic properties, including Young's Modulus (YME) along with porosity data, have been used in two wells to explore the potential relationship between micritic fabric, porosity, permeability and elastic properties. With the evolution of micritic fabric from anhedral compact to polyhedral / subrounded, Young's Modulus decreases with increasing porosity, indicating a decrease in the overall stiffness of the rock. Based on these two learning wells, specific porosity and YME cut-offs have been identified to discriminate the various micrite fabrics. Those cut-offs have been successfully tested in four other wells used as a blind test for the vertical prediction of the micritic fabrics, in which accurate predictions reached up to 90%. Following these results, porosity and YME cut-offs have been used to produce the first model of the distribution of the various micritic fabrics at the field-scale. These results have a fundamental impact on how sedimentologically homogenous microporous limestones can be described and predicted at the well and field-scales, especially in the context of exploring tight carbonate plays associated with intrashelf basins.
Smart and Innovative Approach that Makes Multilateral Well Construction Efficient and Economical for Worldwide Application
Authors: Kashlev Alexander , Fedotov Andrey , Philippov Alexander , Sayapov Ernest , Moiseyenkov Alexey
Published: November 2019

Global depression in the oil market has recently been the main driver in forcing oil companies to discover more efficient solutions to produce hydrocarbons, as well as to optimize existing strategies and practices, whereas multilateral and branched well completion technologies act as a tool for improving performance of both new and existing well stocks.

These services have been among the premium products offered by oilfield service majors. High cost of this service derives from a limited number of players that are capable of offering and executing such high technology operations, as well as from insufficient field exposure making each implementation very unique and therefore expensive.

The advantages of multilateral wells are well-known in the industry. The most obvious ones are: CAPEX savings on upper completion.Step increase of the drainage area.Wells infill drilling without expanding surface infrastructure.
Rock Type Prediction Using Democratic Neural Networks Association DNNA: An Alternative Method to Describe Clastic Fillings in Ordovician Karsted Carbonates within a Region of the Tahe Oilfield, China
Authors: Mendez Jose Nicanor , Jin Qiang , Gonzalez Maria , Zhang Xudong
Published: November 2019

This study outlines a probabilistic model based on artificial neural networks applied to the very deep karsted carbonates of the Ordovician Yingshan Formation, which represent significanct reservoirs within a region of the Tahe oilfield, Tarim Basin, China. The complexity of rock type prediction and distribution of paleokarst fillings hosted in cavities, drives the need to apply new techniques for identifying more plays. This investigation focuses on a karsted interval located between the reflections of unconformities T74 and 76. The analysis was conducted using acoustic impedance (P-wave) and amplitude seismic attributes, processed from a 32-bit seismic dataset (Poststack). The methodology also includes conventional wireline logs from 28 wells adjusted to lithological descriptions of cores. Democratic Neural Networks Association (DNNA) is the proposed method for rock type prediction in karsted carbonates that simultaneity utilizes 3-D seismic data and well data. Based on sedimentological descriptions, the karst facies are classified in six types of lithofacies: mixed siliciclastic and carbonate (e.g., calcarenite and conglomerate), limestone, very fine-grained sandstone, mudstone, breccia, and unfilled. According to identified lithofacies, a clustering analysis is performed using the followings logs: Gamma Ray (GR), Deep Resistivity (RD), Neutron (CNL), Density (DEN), Sonic (AC), Potassium (K) and Thorium (TH) from Spectral Gamma Ray. Subsequently, the outputs are simplified for selecting the model most representative of lithofacies. Once adjusted data in commercial package, a training set and stabilization geometry involving seismic attributes constrained by interpreted seismic horizons are processed. The extracted seismic traces along borehole trajectory after processing demonstrate a good match with analyzed data, where the predicted maximum probability and class probability tracks vary with respect to lithofacies. Making time slices on the computed volume are observed to estimate effectively the probability of karst facies away from the wells. The outcome of this workflow is a probabilistic facies volume that provides appropiate description of clastic rocks that cover paleokarst fillings essentially in the run-off subzone. The model indicates that mudstone facies are the most prevailing and better proportions of siltstones or sandstones facies are distributed to southeast of area. This study concludes that in determining clastic lithofacies distribution, employing several neural networks running in parallel that simultaneously learn from the same dataset through different strategies is an effective tool. To date, there has not been any study on rock type prediction using DNNA in karsted carbonates. The results represent a significant contribution to the collection of geosciences on characterizing this type of reservoir.
Successful Discoveries Using Novel DHI Technology Based on Seismic Resonance and Dispersion
Authors: Skantze Kristofer
Published: November 2019

A new technology that analyses dispersion events in seismic data is presented. The technology aims at identifying both reservoirs and also the likelihood of any presence of liquid hydrocarbons within them. This paper details the science on which the technology is based and empirical results from usage of the technology.

Presence of strong wave dispersion in seismic data has analytically and in tests been seen to correlate with high porosity and permeability formations. A lack of dispersion has conversely been seen to correlate with low porosity systems. Furthermore, a high viscosity fluid in a poro-elastic system has been seen to cause higher dispersion effects compared to brine. This permits derisking of reservoirs to identify locations with high chance of liquid hydrocarbon.

Resonance wave systems are abundant in sedimentary rock. The measurement of resonance waves permits the study of otherwise weak frequency shifts in seismic data, which can then be used to search for reservoir rock and liquid hydrocarbon.

Velocity dispersion and resonance wave analysis of seismic data requires carefully selected wavelet based spectral decomposition methods. Results from a commercially available technology presented in this paper have shown a need to prioritize high accuracy spectral decomposition methods that are able to identify minute dispersion events. These methods are often very computationally demanding. Therefore, those methods need to be selected that ensure highest accuracy while optimizing for speed.

A dispersive event occurs when an incoming P-wave propagates through a heterogeneous porous media due to mesoscopic flow. Dispersivity contributions may also stem from localized effects such as Krauklis waves. The level of dispersivity has in models and field tests been identified as a function of the reservoir porosity, permeability and fluid viscosity. Empirical results from the technology presented here, suggest the ability to identify reservoirs and frequently also their fluid content using dispersion analysis of seismic data.

Case study results using the commercial technology are presented over both discovery and dry wells in Norway and Oman. The results show how new insights into poro-elastic lithology can be provided and also the technology's potential to contribute to an improved overall prospect derisking and field delineation with respect to fluid content.

The technology demonstrates the ability to extract additional information from seismic data sets and thereby further the geological and geophysical subsurface interpretation and modelling.
Enabling Production Logging in Commingled Flow During HPHT DSTs Allows Critical Dynamic Data Integration for the Khuff Formation in the UAE
Authors: Sookram Neil , Steiner Stefan , Basioni Mahmoud , Menon Pradeep , Noble Reed , Al Afeefi Baraka , Jabbour George , Yaacoub Michel
Published: November 2019

The United Arab Emirates’ strategy to increase gas production, reduce dependence on pipeline imports and become a net exporter of this commodity has led to various important reserve discoveries. Appraisal wells drilled in gas formations such as the Khuff require both static characterization as well as dynamic data integration to improve the overall reservoir modelling in these complex tight reservoirs.

Drill Stem Tests (DST) performed on Khuff appraisal wells provide important dynamic data, however in commingled flow tests more detailed information than that obtained from downhole pressure measurements and surface flow rates is required for a representative dynamic downhole characterization. Production logs (PLTs) can provide the required downhole fluid and flow profiles to differentiate inflow from different reservoirs or individual perforation zones. Such operations can become more complicated in the deep and high temperature Khuff reservoirs, especially when running through the small internal diameters in the DST bottom hole assemblies.

The importance of PLT flow profile data for Khuff appraisal wells was recognized early on as a means to help investigate the formation heterogeneity, and the possible influence of natural fracture networks on reservoir productivity. PLTs were included in the DST programs for the appraisal wells, with the next step being preparing logging procedures and equipment to undertake operations as efficiently as possible. This preparation resulted in multiple production logs being successfully acquired in both vertical and deviated wells, along with logs prior to and after acid stimulation, providing invaluable and often surprising insight into the reservoir behavior and feedback for the static reservoir characterization. Along the way various important lessons were learnt that required modifications in some procedures to increase efficiency or reduce operational risks in the difficult downhole conditions.

This paper will review some of the production log results and discuss the lessons learnt with the objective of making this type of dynamic data acquisition more visible as a very feasible activity to help improve reservoir characterization even under difficult conditions of logging through drill stem test strings into deep, high temperature reservoirs.
An Accurate and Reliable Correlation to Determine CO2/Crude Oil MMP for High-Temperature Reservoirs in Abu Dhabi
Authors: Alshuaibi Muataz , Farzaneh Seyed Amir , Sohrabi Mehran , Mogensen Kristian
Published: November 2019

Minimum miscibility pressure (MMP) is an important parameter in the design of a successful miscible gas injection project. It is common industry-practice to infer MMP from a series of carefully designed slimtube tests, but there are cases where a quick and rough estimate of MMP is required to screen for potential application of miscible gas injection.

Mathematical correlations are attractive because they require few input parameters, little information about the fluids, and are quick and easy to use. Whereas MMP using hydrocarbon gas or nitrogen can be predicted with relative confidence using standard correlations, the same level of accuracy is not found for correlations predicting CO2 MMP, in part because of a more complicated temperature-dependent mass transfer.

This study is part of an ongoing effort to evaluate miscibility conditions using a variety of injection gases across the ADNOC reservoir fluid portfolio. We have tested the most common existing CO2 MMP correlations against measured MMP data from slimtube tests for a large number of Abu Dhabi reservoir fluids. The results show that none of the existing correlations can accurately predict MMP for these crude oils and we believe that this is attributed to the fact that most available correlations were established based on reservoir temperatures much lower than the typical temperature conditions of 250 °F found in many Abu Dhabi reservoirs.

We therefore propose a new correlation for estimating CO2 MMP with particular emphasis on high-temperature fluid systems. The new formulation has been developed based on multiple-parameter regression of measured data as a function of temperature, saturation pressure and reservoir fluids composition. In addition to the existing data sets available in the literature, we performed 17 additional slimtube experiments on different Abu Dhabi reservoir fluids to enlarge the parameter envelope and increase robustness of the model. The proposed new correlation predicts CO2 MMP within 6.4%. To constrain the correlation, we performed a series of EOS-based MMP calculations for several fluids in the temperature range of 100 to 350 °F. These calculations confirm that MMP attains a maximum value around 320 °F.
Learn, Play and Compete: A Case Study of the Gamification of Professional Training
Authors: Al-Readean Muhammad
Published: November 2019

Gamification of professional training is a new trend that focuses on promoting motivation, engagement and competition among training participants by integrating game elements into professional training. The lack of widespread adoption of gamification in training in oil and gas industry in spite of technical and technological advancements in other areas requires careful consideration.

A new course gamification process has been adopted to map professional course learning requirements into game objectives, course modules into levels and policies into game rules. An individual scoring mechanism through the notation of experience gained (XP) with ranking leadership board has been used. In each course module or game level, the participants are challenged to solve timed scenario-based puzzles with increasing level of difficulty. The participant who solves a puzzle will score gained experience points that is recorded in the leadership board. These scenario-based puzzles are derived from real-world situations that participants may face doing their jobs. These puzzles or quests promote inductive and deductive reasoning and ensure effective interactive learning experience. In addition, the training participants, as decision makers, were given the opportunity to design the last stage or module of the course using a survey to collect their feedback.

The approach has been adopted in the material of one petrophysical software application training. The course participants showed a great engagement and interaction with more than 90% agreement about the effectiveness of the approach. Clearly, the gamification of the course must not interfere with linearly progressive delivery of the material. The courses adopted a balanced approach to avoid the deviation from the initial overall educational objective. This experience supports the introduction of more sophisticated and advanced gamification mechanisms such as in-application automatic grading mechanism and the use of Augmented Reality (AR).