A need was felt in ADMA OPCO for a Well Integrity monitoring and management tool which would, in a single document, capture and present the entire Well Integrity status of the well and make it available for the senior management on a click of a button; short and long term actions are well defined and clearly assigned. A similar document had been proposed and implemented for other company assets such as pipelines and pressure vessels.
Since 2003, ADMA OPCO had a legacy Well Risk Ranking System based on the ADNOC 5×5 risk matrix, which classified wells into high, medium and low risk categories. The system captured data such as Xmas Tree/Wellhead valve status, Wellhead cavity status, DHSV status, annulus pressures and any down-hole issues such as corrosion or communication. The Well Integrity Passport enhanced the risk ranking concept by taking into account the business and HSE aspect of a well. Wells with higher production or injection potential are ranked accordingly higher on the vertical axis. Similarly gas wells are ranked higher than oil or water injector wells due to their potential HSE impact in the event of a failure. The horizontal axis is the probability or the technical axis which takes into account the technical and barrier status of the well in terms of the health of various components. The passport also contains a well barrier sketch defining the well barrier envelopes (primary and secondary barriers) and their status. The passport is made available to the senior management using a web based interface called the IDBMS. The overall integrity status of wells or the status of any individual well can be seen at any time upon the click of a button.
Based on the new system, all the wells in the two main offshore fields of ADMA OPCO were reassessed. The results were similar but not exactly as from the previous risk ranking system.
The system has added great value because it is designed to produce a semi-quantitative risk score which can be a tool in prioritizing the required repairs or monitoring activities.
Plant Turnarounds (TA) are by themselves complex maintenance projects and a back to back turnaround in the Company in 2012-13, without any doubt, threw many challenges that was to be managed well to achieve very stringent HSE targets. This challenge lead the TA core team to an innovative and proactive method on the HSE management aspects that lead to every Contractor employee going back unharmed after 75 days of hard work. The startup of the Ethane unit crackers (EU1) in a record time of 28 days and 18 hours could only be achieved with the philosophy of "First time right" principles embedded within the activities and HSE and Quality Plan, which was executed well by all the team members including the Company leadership team, the employees and above all the Contractor employees who embraced this approach enthusiastically.
This paper aims to present, in a practical approach, the application of basic HSE principles and HSE management elements to the Management of Contractors and Sub-Contractors for a Major turnaround of Olefins and Poly Olefins Plant in the year 2012-13. This application can be understood and emphasized in the various stages of a turnaround: planning, pre-turnaround, shutdown, maintenance itself, commissioning, and startup of the plants.
Steiner, S. (ADCO) | Raina, I. (Schlumberger) | Dasgupta, S. (Schlumberger) | Lewis, R. (Schlumberger) | Monson, E. R. (ADCO) | Abu-Snaineh, B. A. (ADCO) | Alharthi, A. (ADCO) | Lis, G. P. (Schlumberger) | Chertova, A. (Schlumberger)
ADCO started its unconventional exploration campaign in 2012 targeting the tight carbonate sequences known as Wasia Group, onshore Abu Dhabi. A front-end loaded data gathering strategy was employed to acquire extensive latest generation logging data tailored for unconventional reservoirs. In a number of wells the entire reservoir section was cored, often up to 800 ft per well, leading to more than 3000 ft of core retrieved to date. ADCO applied unconventional core analysis technologies, such as retort analysis, to generate the optimal core results. Key parameters such as effective porosity, pore size distribution, TOC, source rock maturity, mineral compositions and fluid saturations were determined from logs and core data (where available).
This paper will focus on the petrophysical challenges during the evaluation of the Wasia Group. We will demonstrate that conventional core analysis techniques have only limited applicability, whereas core analysis techniques designed specifically for unconventionals provide more relevant results. A log analysis methodology centered on the application and importance of NMR in unconventional liquid plays is presented. Porosity data measured through retort analysis provide an excellent fit to NMR log-based porosity measurements. Conventional core analysis results generated a poor fit to log porosity, and the resulting values exhibited scatter with a large standard deviation.
Log data-derived rock typing was performed. It is based on principal component analysis of the reservoir section. Rock classification may help in selecting suitable zones for hydraulic fracture initiation.
Lessons learned from the initial wells for core recovery and analysis techniques are summarized below and have been implemented in later wells: Preserve part of the core for robust saturation measurements. Stop acquisition of conventional poro-perm data Focus on unconventional-specific retort-based techniques for core petrophysics Focus on pulse decay permeabilities Use scratch test to aid in core analysis sample selection process, especially for rock mechanics Add core
Preserve part of the core for robust saturation measurements.
Stop acquisition of conventional poro-perm data
Focus on unconventional-specific retort-based techniques for core petrophysics
Focus on pulse decay permeabilities
Use scratch test to aid in core analysis sample selection process, especially for rock mechanics
The complete integration of core and log data has allowed for a thorough assessment of the unconventional hydrocarbon potential within the ADCO concession.
"I trust that this sort of nonsense will never happen again"- reportedly said the Coroner at the investigation enquiry of the very first motor vehicle accident in 1896. Since then, and until the present day, motor vehicle fatalities remain one of our primary workplace concerns in the Oil and Gas industry. According to the latest IOGP statistics, 7.7% of our industry's work-related fatalities occurred due to land transport activities. Land transport incidents also accounted for 2 out of every 5 fatal work injuries in the US under OSHA incident reporting guidelines. This concern is not limited to the Oil and Gas sector or the United States but is notable in other industries and geographies across the globe.
In risk management, an "inherently safer" approach implies an attempt to eliminate or, at least, reduce the severity and likelihood of incident occurrence through careful attention to fundamental design and layout. In this context, we examined whether this approach can be applied and be effective in managing transportation safety where, historically, most of the responsibility for safe driving has been placed on the individual driver and less on the design of the transportation system and features of the equipment. We challenged the premise of our entire transportation system and adopted a more holistic "safe in design" approach which not only focused on the human behavior and attitude of the person behind the wheel, but designed a safer sytem for the driver, including driver support, operations management and vehicle safety aspects of the transportation process.
Baker Hughes Middle East Asia Pacific (MEAP) HSE organization embarked on the ambitious undertaking to overhaul the transport safety management program by addressing the three critical aspects of Driver, Vehicle, and Journey Management system by doing the following: Upgraded our fleet management system to become electronic and capable of not only passively tracking but proactively alerting to potential areas of concerns, which would further trigger immediate interventions. Created a new department with several organizational layers: journey management operators, transport supervisors, driver trainers, etc. Developed a new set of rules and communicated to them to driving and management level personnel. These rules provided them not only with more authority but also with increased responsibility and accountability. Management must not only follow policy and procedures requirements, but also ensure they do not put their drivers in a "no-win" situation by compelling them to take unnecessary risks when planning a journey. Our driver training program was upgraded to address critical common safe driving techniques and skills, specific regional hazards, while improving the quality of training. Enhanced engineering requirements have been adopted to increase occupant safety, (e.g.: rollover protection).
Upgraded our fleet management system to become electronic and capable of not only passively tracking but proactively alerting to potential areas of concerns, which would further trigger immediate interventions.
Created a new department with several organizational layers: journey management operators, transport supervisors, driver trainers, etc.
Developed a new set of rules and communicated to them to driving and management level personnel. These rules provided them not only with more authority but also with increased responsibility and accountability. Management must not only follow policy and procedures requirements, but also ensure they do not put their drivers in a "no-win" situation by compelling them to take unnecessary risks when planning a journey.
Our driver training program was upgraded to address critical common safe driving techniques and skills, specific regional hazards, while improving the quality of training.
Enhanced engineering requirements have been adopted to increase occupant safety, (e.g.: rollover protection).
This paper explains the changes which allowed our region and the company as a whole to accomplish outstanding results: improvement of motor vehicle rate by 58% and prevention of 63 motor vehicle accidents within one year.
Pushkarna, A. (National Drilling Company) | Mathew, R. (National Drilling Company) | Al-Suwaidi, A. S. (National Drilling Company) | Malhotra, U. N. (National Drilling Company) | Mukhtar, A. (National Drilling Company) | Belbissi, F. (National Drilling Company)
Organizations are always looking to approach production in innovative ways that will boost the results, increase productivity, cut down slack time and increase revenue while keeping the risks of HSE failures and asset integrity incidents down to a minimum. The challenges are greater when time pressure comes into play. Consequently when an operational rig is shutdown for maintenance it becomes important to execute the project in a shortest time while ensuring uncompromising HSE, Quality and Asset Integrity standards.
NDC examined its practices and put in place an innovative process and named this initiative Excellence in Projects (EiP). Simply put the Excellence in Projects follows the typical path of planning, execution, reviewing, and then once again planning. It follows the classic Deming cycle of PDCA and translates this in project terms.
Starting with an assumption of a "perfect world" with unlimited resources in terms of funds, material and manpower, the EiP allows teams to plan a Perfect Project on paper. The requirement is to come up with a perfect time and quality output – best quality with the shortest time. The output of this ideal project is then transferred into real-life actions taking account of the actual projects constraints. The final result is the happy medium of truly achievable goals against challenging odds. The project is allowed to run and the lessons learnt are captured on completion and feed into the next project thus ensuring a continuous improvement cycle at all times.
This paper is a case study on the successful implementation of this EiP project, using set KPIs and scoring systems, yielding excellent benefits not just in time and cost saving but also Team Building, Quality, Reliability and above all HSE and Asset Integrity.
This paper aims at predicting the fracture system associated with the structural development of the Shah Structure in relation to a deep-seated basement fault. It discusses the possible geometry, frequency and fracturing modes, and the development mechanism of the fracture system revealed throughout a set of analog models, which emphasize the link between the basement fault and the sedimentary cover in a timely manner construction.
A 3D seismic data was used to construct a series of systematic scaled analogue models to reconstruct the structural evolution of Shah Anticline in association with an oblique sinistral strike-slip movement along basement fault, which induced both a strike slip movement in- and shortening of the cover sand layers. The deformation that was made by moving one of the basement plates in an oblique slip along the basement fault, resulted in an open anticline (box fold), which resembles the Shah Structure.
Analog modeling results presented here reveal that fractures associated with the asymmetric anticline have developed in different locations, and possessed different geometries and modes. As anticipated, both tensile and shear fractures have developed in different areas within both the crestal parts of Shah Structure and within its limbs. However, the asymmetrical geometry of the model-anticline is reflected in the fracture distribution, trend and frequency. The steeper limb of the anticline bear more developed fractures than the gently dipping limb. The asymmetry of the anticline is not equally well displayed by the post-erosional units above the unconformity "model Simsima", where a gentler anticline is displayed. Hence within this gentle part of the model-anticline the fracture pattern is less developed, less frequent and evenly distributed. Such vertical and horizontal asymmetries in fracture pattern (geometry, frequency and mode) seen in these analog models are expected to have in reality developed in the Shah Structure.
This new modeling approach has helped predicting the occurrence of different fracture system including geometry, frequency and fracture mode in different areas within Shah Structure. The predicted fractures have significant implications for exploration and field development plans of Shah Structure and those situated at the vicinity within Onshore Abu Dhabi.
Shi, Y. (Research Institute of Petroleum Exploration & Development, CNPC) | Yang, X. (Research Institute of Petroleum Exploration & Development, CNPC) | Zhou, F. (Research Institute of Petroleum Exploration & Development, CNPC) | Gao, Y. (Research Institute of Petroleum Exploration & Development, CNPC) | Lian, S. (Research Institute of Petroleum Exploration & Development, CNPC) | li, x. (Research Institute of Petroleum Exploration & Development, CNPC) | Han, X. (Research Institute of Petroleum Exploration & Development, CNPC)
Horizontal well and acid stimulation are the essential technologies for the development of complex carbonate reservoir. However, it is extremely difficult to conduct effective stimulation in horizontal wells with a long interval because the traditional acid systems without diverting performance can only flow into the high permeable formations, leaving the damaged formation untreated. That is why the long interval wells with high heterogeneity need to be stimulated by diverting acid system. Many diverting acid systems or diverting agents have been developed in recent decades. Whereas, last generation diverting systems always cause serious damage to formation, such as gelled acid based on polymer. In addition, many systems will lose their diverting performance at high temperature.
This paper studied some kind of residual-free fluid systems for both acid treatment and fracturing in order to develop no-damage/reduced-damage and high effective stimulation techniques for long interval wells. It is designed to conduct uniform stimulation in a long distance wellbore with the assistance of diverting performance of some special chemical agents, which can work at high termperature and leave no damage in formation. No-damage stimulation includes: Temperature-controlled deep-diverting acid system (TCA); pH-controlled self-diverting acid system (DCA), and Fracture reorientation technology based on degradable fiber (RDF). This series of technologies can generate fracture networks to enhance the stimulated reservoir volume through fracture reorientation and diverting acidizing with the help of special residual-free fluid system, leaving no damage in formation.
This series of techniques had been applied on 921 wells from 10 oil/gas fields in China and 7 oil/gas fields in Kazakhstan, Iran, Iraq, Syria and Turkmenistan.
The Abu Dhabi onshore Anticlinal Fields are trending NE-SW and N-S, with their eastern flanks being of steeper dip (~3 ° -5°) than their western flanks (~1° -2°). In previous research, kinematics, and mechanics of onshore Abu Dhabi folded anticlines had not been addressed. The main objective of this paper is to understand the kinematics and mechanics of the folding systems.
A new approach to understanding the mechanical evolution of these anticlines is presented here through the use of conceptual modelling and theoretical approaches. A combination of geological and geophysical tools is used for determining the direction of the shear stresses along the flexural slip planes. Although textural evidence, such as karstification and diagenesis, suggests local material redistribution on different scales, compositional trends support negligible volume flux at the scale of the anticlines. The preservation of bed length and bed thickness in most of the onshore Abu Dhabi Anticlines requires the development of bed-parallel shear. Abu Dhabi Anticlinal fields are mechanically evolved by flexural shear and flexural slip folding, which is characterized by differential simple shear along the bedding planes, where deformation is concurrent with the diagenesis. The layered horizons of these folds are mostly of carbonates, where the competency contrast is low and the friction between the layers is high leading to flexural shear. In the locations, where incompetent shale layers alternate with the carbonates, flexural slip is considered - although this is very limited within Abu Dhabi anticlinal structures. In these folds, the bedding planes of less competent layers act as boundaries of shear zones. Therefore, most of the internal deformation occurs within the less competent layers by partial recrystallization and development of fractures. However, the competent layers undergo pressure solution, development of sigmoidal extensional fissures, and stylolites in most cases. Thus, the overall folding system is heterogeneous and the competent layers simply slide over one another. The dominant direction of the over-riding shear is directed toward the fold axial surface and the stresses are released along the bedding plane discontinuities. The bedding plane discontinuities are considered to represent the finite neutral surface of the fold. Folds having parallel geometrical forms have opposite directions of structural shear in transtensional and transpressional regime.
In the Abu Dhabi flexural slip shear folds, deformation in the hinge zone is characterized by pure shear, and deformation on fold limbs is characterized by components of both simple and pure shear. Strain models of pure bending, layer-parallel shear, and shear parallel to the hinge plane are shown to be the main mechanism of these folds. Preservation of these will play an important role in revealing a new play concept for the Abu Dhabi fields.
Otevwemerhuere, J. (Addax Petroleum) | Nwosu, C. (Addax Petroleum) | Olare, J. (Addax Petroleum) | Jefford, Leigh (Addax Petroleum) | Parkins, Steve (Addax Petroleum) | Cavalleri, C. (Schlumberger) | Shrivastava, C. (Schlumberger) | Espinosa, H. (Schlumberger) | Mougang, M. (Schlumberger)
Low resistivity low contrast (LRLC) reservoirs have been successfully produced for many years; however detection and detailed description of their properties and potential would remain a challenge in absence of an exhaustive formation evaluation program. Proper understanding of the geological evolution of such reservoirs to explain their distribution and variations in petrophysical properties is also vital.
Low resistivity pay reservoirs encountered in West Africa are often characterized by variation in resistivity values in vertical and horizontal directions due to fine grains and conductive layers within the coarse grained sands and clearly marked sand-shale laminations. This is accurately solved by tri-axial induction resistivity measurement in combination with high resolution measurements able to define any contributing layer level-by-level through robust anisotropic interpretation methods. However, heterogeneity, mixed clays effect, and complexity in rock texture require new technology and innovative interpretation models in multi-domain approach.
Advances in logging technologies, interpretation software, and analytical methodologies enable better and more refined reservoir models to be fashioned and tweaked as needed on a case-by-case basis. The case study analyzes log responses, implication of heterogeneity and mixed clays content on the generation of LRLC pay reservoirs in deltaic environment offshore Nigeria.
Precise application of advanced log measurements and integration of core data in a common workflow, built around the concepts of evolution of LRLC reservoirs lead to accurate pay quantification. Borehole image interpretation suggests that the low resistivity contrast is attributed to dispersed clays coating around the sand grains in the toe part of a delta front in major coarsening up and feeble fining up sequences. This is also confirmed by variations of elastic properties of the matrix.
Petrophysical logs recorded at high resolution correlate inferring the main causes of LRLC pay are clay content and distribution, and small grain sizes intermingled to the reservoir rock, hence resulting in low resistivity values in all directions and drastically increased irreducible water. The logs based model is confirmed by calibration to core analysis results. The confident results of the study confirm the power of collaboration between petrophysics, rock mechanics and geology in innovative interpretation workflows for enhanced reserves estimate and Producibility prediction in heterogeneous media.
Karachaganak field, brought on stream in 1985, is one of the largest accumulations of gas-condensate in the world. Located in the northern Pre-Caspian Basin (Kazakhstan), the field is a Permo-Carboniferous isolated carbonate platform, with a hydrocarbon column of about 1500 m.
The current development focuses the oil rim with gas injection in a confined area of the Platform Interior implemented since 2004. Among the future development scenarios under consideration, an increase of gas injection in different areas of the field was evaluated with the scope of maximizing liquid recovery and keeping the production plateau. The internal reservoir architecture is indeed very complex: an initial development of aggrading mounds is followed by prograding clinoforms passing to cyclic, grain-dominated platform interior sediments. The resulting reservoir quality is quite heterogeneous, with low porosity, but locally high productivity when affected by micro-fractures and vugs. The analysis was performed considering both incremental volumes of injected gas and the uncertainties affecting the reservoir to obtain a ranking which takes into account additional liquid recoveries and relevant risks. Eventually, the analysis led to a proxy function which, through a mean-variance optimization approach, was used to estimate the most favourable gas injection configurations, reaching the best compromise between recovery and uncertainty.
In conclusion, the analysis highlighted pros and cons for each reservoir area, offering a better view to optimize the future development. The depositional region where the injection was already implemented appears to be a good candidate; other areas, although affected by a certain degree of uncertainty, are also promising from the recovery point of view, while some other regions, characterized by high compartmentalization, seem to be less interesting.