bluuebunny/crossref_metadata_2025 huggingface dataset:
Interaction Between Hydraulic Fracture and Natural Fracture - A New Prediction Model by Adaptive Neuro-Fuzzy Inference System (ANFIS)
Authors: Chen P. , Rahman M. M. , Sarma H. K.
Published: December 2014

Hydraulic-fracturing (HF) treatments have become an essential technology for tight gas field development. Tight gas formations often contain natural fractures (NF). In presence of NF, more complex fracture networks may form during the hydraulic treatment. The interaction between fractures may alter the way the hydraulic fracture propagates through the formation, causing a complex network of fractures, which can significantly influence the overall geometry and effectiveness of hydraulic fracture. The hydraulic fracture may cross, dilate or slip into the fracture plane upon its arrival at the natural fractures. Although there have been studies on investigation of the interaction between HF and NF, most of them cannot be applied reliably due to the inherent assumptions in the analytical formulation. In cases of laboratory studies, the limitation of the equipment could also be a factor. With this study a multi-ANFIS model is established to predict the interaction between HF and NF. The advantage of this model is that it is a data-based model. Therefore, as long as there are reliable data the model can work smoothly and easily, so that it can predict the interaction in real time. Results show that the dilation and slippage will be more likely to occur when the approach angle is very low. Whereas, in the case of higher differential horizontal stress, it is more likely that the cross interaction will happen. The significance of this work is to help to predict the interaction between HF and NF, thus optimizing the hydraulic-fracture treatment design parameters in a naturally fractured tight gas reservoir. Insightful parametric sensitivity analyses will also be presented. This model could also be used to study the potential of the deep UAE gas sands, which are naturally fractured.
Wellbore Monitoring in Carbonate Reservoirs: Value of DTS in Acid Stimulation through Coiled Tubing
Authors: Gorgi Sam , Medina Eber , Gleaves Jorge , Acuña Juan , Perera Luis , Rodriguez Miguel
Published: December 2014

In acid matrix stimulation, the correct placement of the injected fluids is essential. Several diversion and placement techniques are often applied to obtain the desired fluid placement (Glasbergen and Yeager 2010). Distributed temperature sensing (DTS) and coiled tubing (CT) pressure, temperature, and collar locator tools were used to monitor the fluid placement and effectiveness of the diversion process.

Real-time monitoring was required as part of the overall reservoir management strategy for the Tecominoacán 705 well. The CT service provided ideal conveyance for DTS in this highly deviated and depleted well. In a distributed-temperature survey, the fiber optic served as the sensing element, and combined with CT conveyance and pressure/temperature/collar locator tools, enabled continuous wellbore temperature monitoring across the entire horizontal while pumping a stimulation treatment through an annular space consisting of acids and diverters. It also allowed real-time decision making based on the actual measured injection profiles.

This well was highly deviated in a carbonate reservoir, completed with 675 m of 4 1/2-in., 12.7 lb/ft liner and swell packers, with 150 m of tubing conveyed perforating (TCP) perforations distributed in six intervals. The DTS combined with CT tools provided accurate monitoring of the stimulation treatment, which was pumped through the annulus between the production tubing and CT. With the DTS service, it was observed that the stimulation fluids were injected only at the heel of the well, which was acting as a thief zone as a result of the presence of highly conductive natural fractures. Several stages of diverters were pumped to attempt to divert acid from the heel to the tip of the well, without success. The decision to cancel the final acid stages saved USD thousands in fluid costs. Mixing the acid on-the-fly using special blending equipment allowed the optimization of resources based on real-time decisions influenced by the DTS injection analysis.
From Horizontal to Vertical Leadership Development
Authors: Flahive Tadhg
Published: December 2014

We are now living in a VUCA (volatile, uncertain, complex, ambiguous) world. The nature of challenges faced by current leaders is constantly evolving while the methods most organizations are using to develop leaders are generally staying the same. The renowned American Business Theorist, Chris Argyris, used the analogy of single versus double loop learning. In the former adjustments are made to existing techniques. The latter involves changes to the assumptions and thinking upon which programmes are built. For organizations to survive and prosper in this new world, double loop learning is essential.

Leaders now have to do more with less. More adaptive and complex thinking abilities are required. There is a need to grow bigger minds. "There are no boundaries anymore" (Jeff Barnes, Head of Global Leadership, General Electric). New adaptive leadership competencies, skills, abilities and attributes are now needed in interconnected global work environments. A paradigm shift has to ensue and be manifested in both the constructs and delivery of leadership programmes. "Future generations will be living in a world that is very different from that which we are accustomed to. It is essential that we adapt ourselves for this new world" (His Highness Sheikh Zayed Bin Sultan Al Nahyan, founding rule of the UAE).

This paper will provide clear evidence of how one of ADCO's main internal leadership programmes "Leading People Performance" (LPP) has re-aligned and re-focused its content along four leadership development trends: transfer of ownership to the individual; innovation and technology; collective leadership; alignment to work context.

The paper will first look at the reasons why many leadership programmes don't work. This will be followed by a clear differentiation between horizontal and vertical leadership development. A detailed overview of the LPP programme will be presented. The final section of the paper will provide examples of how LPP incorporates elements of vertical leadership development within the aforementioned four leadership development trends.
Abnormal Reservoir Property Changes of Lower Cretaceous Carbonate, Gas Reservoir Onshore Abu Dhabi, UAE
Authors: Al Hashemi Hussain H. , Masoud Rashad , Al Ammari Khalid , El Gohary Mohamed , Moen-Maurel Laure
Published: December 2014

Carbonate Reservoirs are well known for their heterogeneity in terms of porosity and permeability. In this field case from UAE onshore a sharp degradation of petrophysical quality was noted at the gas-water contact, in relation to diagenetic cementation, and led to an independent modelling for the aquifer, as well as an independent modelling of the reservoir with a data filter for the gas pool only. A merge of the 2 grids was then performed.

In this field a major bias on well data distribution from crest to aquifer affects the geostatistical histogram evaluation: wells are concentrated in the crest down to mid-flanks while there are few wells from mid-flanks to the aquifer. Consequently distribution histograms of petrophysical data from the whole model should not respect well data histograms (whether, core-, log- or cell-derived).

The methodology of separating gas and aquifer modelling, and of separating well derived histograms from model-derived ones led to the following results:

– Better capture of the reservoir degradation with depth in the gas pool, – Better capture of the sharp degradation break in the aquifer.

This paper is focusing on the methodology of how to build two separate models in the gas pool and the ‘aquifer for each petrophysical property and how to combine them in one property model to honour reservoir heterogeneity.

Integration of all data at all scales and constant QC between database sources (logs, cores, seismic, dynamic history) were the means to produce a geomodel capturing the key heterogeneities of the reservoir, those with major impact on fluid front migration during production.
Challenges and Redesign Requirements Drilling High Angle Surface Holes in Giant Offshore Oilfield
Authors: Ryan J. T. , Grini M. , Al Junaibi H. , Al Katheeri Y. , Edwards H. E. , Day T. , Rachi H. , Chandran K. , Espeland K.
Published: December 2014

The island development strategy of the giant offshore oilfield requires the use of extended reach drilling (ERD) design wells. Compared to the typical wells drilled from the wellhead towers in the same field, higher inclinations are required in both the surface hole and intermediate hole to facilitate drilling three dimensional wells of more than 35, 000 ft. While the challenges of drilling the intermediate hole at higher angles had been identified early on due to field experience, the challenges leading to stuck pipe events encountered in the surface hole were not anticipated due to limited experience drilling high angle surface holes in the region.

Historically total loss of returns has been a common issue in the region when drilling the surface hole. Typically when drilling from the Jack Ups, the wells are drilled with sea water and high viscosity sweeps once total losses has been encountered. Any potential aquifer flows are diverted overboard. In order to divert the aquifer flows on the newly built Artificial Islands, the fluids must be pumped 200 or more meters to the gulf. Mud cap drilling (drilling with seawater down the drill string with heavy mud in the annulus to control well flows) was implemented to solve the issue of losses and flows on the island.

The early wells with surface holes drilled at high angle experienced stuck pipe while tripping out of the hole after reaching casing point, leading to significant non-productive time (NPT) and risking project objectives and planned designs. A detailed investigation was performed, including running six arm caliper logs to better understand the mechanism for stuck pipe events. After analyzing and understanding the issue, operational practices and bottom hole assembly designs have been changed to reduce the stuck pipe risk, and specially designed stabilizers have been manufactured and used to mitigate stuck pipe events. Geologically, significant data gathering within the overburden sequence to characterize lithological, stratigraphic, and diagenetic heterogeneities, as well as structural discontinuities, has improved understanding of aspect ratio and vertical scale of features being drilled that may have caused the previous hole morphology effects. No stuck pipe events have been experienced to date in the surface hole due to the same effects after implementation of the new equipment designs and improved drilling practices.
Effective Asset Integrity Management through an Effective Risk Based Inspection Program- ADGAS’ Experience
Authors: Sabry Houssam
Published: December 2014

Abu Dhabi Gas Liquefaction Company Limited (ADGAS) is producing LNG since 1977. ADGAS is the pioneer LNG producer in the Middle East. In 2010 ADGAS started exporting sales gas to Abu-Dhabi through its first gas treatment complex (Offshore Associated Gas). This was followed by the commissioning of additional three gas treatment trains (commissioned in 2013). The total Export gas volume is 1.4 MMM SCFD. During its 37 years of operation, Safe and Efficient production is one of ADGAS core values. Since commissioning of its first two LNG trains and as per the industry practice at that time, time based inspection was being practiced to inspect the static equipment (pressure vessel and piping) for any degradation. Time based inspection generally inspects everything without looking at the risk inherent in an equipment failing; time based inspection is governed by minimum compliance with rules, regulations and standards for inspection. Following time based inspection, where there was no prioritization of inspection activities, this sometimes led to surprises. As The Risk Based Inspection (RBI) approach emerged in the nineties of last century, ADGAS was among the first few companies studying the advantages and implementing RBI. In 1999 ADGAS started its first qualitative RBI. Following the qualitative RBI approach, ADGAS moved towards quantitative and semi-quantitative RBI approaches. Through the implementation of RBI, risk ranking was well established for all static equipment, inspection activities and turn around activities were optimized. Hence, following RBI, receiving surprises leading to unplanned shutdowns decreased if not avoided. This paper presents ADGAS asset integrity management experience moving from time based inspection towards effective RBI approach. RBI experience is being addressed in terms of the different concepts of RBI, different implementation stages, human factor in RBI, RBI lifecycle, implementation and ever-greening.
Internal Chloride Stress Corrosion Cracking of Austenitic Stainless Steel Risk Based Assessment of a Gas Plant
Authors: Sabry Houssam
Published: December 2014

Post commissioning of the new AGDAS gas treatment facility (Offshore Associated Gas (OAG)), several failures in 316L stainless steel piping and equipment occurred. Since OAG commissioning in November 2010 till October 2011, 13 failures were recorded. All failure investigatios concluded that the immediate cause of failure was internal Chlorides Stress Corrosion Cracking (ClSCC). ADGAS considred actions to ensure the safe and efficient operation of OAG. To quantify the inherent risk associated with the operation of OAG assets under the likelihood of failure due to ClSCC, a Risk Based Assessment (RBA) exercise was conducted by an ADGAS multi-disciplinary team.

Results of this assessment were used for as the basis for determining the risk associated with each and every stainless steel asset, prioritise the replacement works and plan for inspection and monitoring. In otherwords, provide the basis to evaluate the extent of the problem and hence put a mitigation plan. A tool for risk (RBA) evaluation of ClSCC was developed in house.

This key activity paved the road towards setting an overall action plan to contain the OAG risk of ClSCC. The action plan has managed to prevent further leaks in OAG. Action plan included the launch of special advanced nondestructive testing program capable of detecting premature stress cracks in stainless steel, temporary composite wrap repairs at specific high risk locations, a dedicated emergency and HSE program in addition to other actions. Chlorides stress cracking leaks could have resulted in major consequences in terms of HSE, loss of production and disruption in gas supply.
Innovative Assessment Approach to Quantify the Impact of Load Additions and Mitigation Strategies on Existing Offshore Platform Structures
Authors: Azouz Amr Mohamed , Aita Raja Srinivasa , El-Khouly Wael Saad , Atia Mohamed
Published: December 2014

Offshore structures usually experience many stages of alterations, modifications, load additions and strengthening work during its operational life to meet increased production plans and/or changes in process/safety philosophies. Significant load increases are likely accompanied with strengthening schemes to cater for such additions. Conventional design methods for assessing these modifications employ linear structural assessment that do not account for actual history of loading/strengthening. Conventional design practices and current design codes do not provide specific guidelines covering the effect of progressive loading and staged strengthening in a manner that ensures accurate distribution of loads into the supporting structural elements. This paper illustrates the benefits of employing progressive loading and staged strengthening over conventional approach. The benefits are highlighted through two case studies involving the Re-assessments of ADMA's Collector Separator Platform (CSP) and Bridge B5 connecting the CSP to Riser Platform. The assessment of these structures utilizing this innovative approach were carried out to demonstrate that these structures are meeting code (API WSD/ISO19902) compliance under the proposed additional loading.
A Risk Management Roadmap for Capital Oil and Gas Projects
Authors: Kenzhetayeva Zarina , Ribeiro Maria T. , Oliveira Nuno , Carvalho Álvaro , Bicho Margarida
Published: December 2014

Project partners want field operators to achieve production targets and deliver projects in the defined timeframe within budgetary limits. However, operators are frequently unable to achieve the goals projected at the launch stage of the project. This compromises the initial project economic value and originates conflicts between partners' anticipations and the actual project outcomes. Such inconsistency is frequently due to wrongful and/or insufficient perception on risk management policies employed by both parties: operators often compromise the application of a holistic risk management framework, by concentrating their efforts around particular project segments, such as HSE, fluids production and/or oil price; partners, being heavily dependent on operator efficiency and competence, have limited tools to control project performance and usually rely or accept selected risk management methods.

This paper presents a general risk management approach for the oil and gas industry based on the knowledge gained in petroleum projects. The proposed methodology offers a coherent approach, which can aid in improving the risk management strategy of both operators and partners. The challenge is in developing a simplistic, but yet effective and dependable method, which can be utilized by consortiums in any oil and gas ventures.

The result of this paper is a Risk Management Roadmap (RMR) that provides all stakeholders with concrete tools to assess and categorize project risks, quantifying their potential economic impact and hold major threats within acceptable levels.

This paper attempts to provide relevant implications for both parties: operators enable an effective communication with partners facilitating a clear and common language for mutual cooperation and progression towards the project targets; partners benefit from taking better informed decisions, protecting shareholders' interests, having stronger control and influence over the desired project outcome.
Talent Attraction and Management of Competencies in Challenging Oil and Gas Environment.
Authors: DORDAN Jean Pierre
Published: December 2014

The Oil & Gas industry is facing increasing challenges with more complex, highly technological oil & gas developments and growing expectations from stakeholders in regards to acceptability and HSE. Major IOCs are facing more competition from NOC in accessing resources and developing reserves and the produced barrels require more technology and expertise than ever. Furthermore, Total, a major integrated international oil & gas company, cannot rely on domestic hydrocarbon resources and therefore need to keep an edge on technology and innovation in order to continue to operate and grow. Key Company objectives to maximize existing production, to economically develop new Projects to increase production level and to renew reserves cannot be achieved by only keeping an edge on technology through extensive R&D, but require highly qualified and competent human resources. Operational Excellence relies on three pillars, well designed, built and maintained facilities, comprehensive procedures, and competent personnel both in Head Quarter and affiliates.

Today, O&G industry is faced with challenges such as availability of competent resources, and competition for talent between competitors, contractors and other industries.

Total has developed a strategy and tools to cope with those challenges articulated around three aspects. –Attract and recruit talents.–Bringing all new recruits to professional autonomy in a reduced period of time–Managing and Developing competencies through a dedicated Company management system
A Novel Fully Plastic Caliper Pig for Low-risk Pipeline Inspection - Design, Characterization and Field Test
Authors: Di Lullo A. , Tasso A. , Cocuzza M. , Pirola M. , Canavese G.
Published: December 2014

Pipe in-line inspection by "intelligent" pigs is a fundamental oil and gas industry practice but still considered as an exceptional operation. In fact, the instrumented pigs addressing such a purpose are expensive and delicate tools with non-negligible operating risks, thus making their deployment rather infrequent (typically, once every several years). In eni we have started a number of R&D initiatives targeted to making pipeline inspection easier and more frequent by significantly reducing the operating risk faced when deploying inspection pigs.

In this context, we present a new, low-cost and low-risk plastic pig with inspection capabilities analogous to those of a multichannel caliper pig (i.e. able to detect, locate and size inner diameter changes and deformations) together with additional features allowing to detect internal roughness changes (e.g. due to corrosion) and perform some pH / salinity determinations, also useful for corrosion assessment purposes.

One implementation of the new tool makes use of a foam pig "body", providing the required push with a good capability to negotiate restrictions, equipped with specialized sensors and modules for acquisition and storage. Another implementation, targeted to gas lines and called "skeleton caliper pig", deploys the light plastic system without any foam pig carrier, pushed by the gas velocity alone, and is suitable to prevent the massive displacement of condensates from gas lines.

The paper describes the design, construction and field testing of this new low-risk caliper pig, together with some comparisons with the information gathered adopting a conventional tool.
Thermal Fatigue in Gas Treater Columns
Authors: Shagar Nabil
Published: December 2014

In aging equipment, failures can occur after long run in operation due to accumulation of thermal cycles. A case study of in-service failure of C4 Treater vessels as a result of thermal fatigue has been studied. Thermal fatigue cracking took place in four C4 treater vessels after 36 years of service life. Cracking took place at the welded attachments, which is typical of thermal fatigue cracking. Failure investigation was done. Vessels repair was carried out to remove all cracked locations till vessels replacement. Unique features of thermal fatigue cracking shall be presented. The effect of surface geometry and design factor on crack initiation and propagation were reviewed. Repair procedure, short and long term recommendations have been concluded to avoid such failure reoccurrence in future. Paper illustrates quantum of the thermal fatigue cycles for this case, other damage mechanisms affecting thermal fatigue, cracking morphology, material of construction of the vessel and effect of stress raisers. Advanced nondestructive testing techniques for premature detection are studied. Factors affecting thermal fatigue in pressure vessels are also discussed. Hence, paper is an illustration of an actual Thermal Fatigue Cracking case study in a carbon steel C4 treater column, how cracking was discovered, metallurgical investigation, repair, advanced inspection techniques and the recommendations to avoid recurrence of cracking in similar vessels under similar conditions.
Utilization of Expanded Polystyrene EPS Waste as Sorbent for Oil Spill Cleanup
Authors: Nasir Mohammad Ibrahim , Hameed Zainab Mohsen
Published: December 2014

EPS is a major constituent of plastic waste. Reuse of waste EPS which is non-biodegradable, to useful products is a way of effective waste management. Oil is one of the most important energy sources but oil spill accidents often take place during the oil utilization process, resulting in threats to the environment. We report the use of EPS waste to obtain an adsorbent material to cleanup crude oil spill from water. The effects of major factors such as sorption time, adsorbent surface areas, kind of surface (smooth or rough) and thermo-modification and mechanical modification (punching holes) were investigated. The experiments carried out with about 0.900 g EPS sorbent were tested for oil sorption for 5 to 120 min at 400 g oil only and at 50 g oil over 800 mL water surface. Oil sorption increases with increasing the sorption time's and surface areas. Surface areas increase with cutting the EPS pieces with serrated edge knife or/and cutting the EPS to 2, 4, 6 and 8 pieces.

Oil sorption capacity (OSC) increased with increasing surface area, and so two pieces have OSC of 1.733 g/g more than one piece of 1.208 g/g of the same weight (0.900 g) and sorption time (5 min). Rough surface of EPS adsorbed more oil than smooth surface. Most of adsorptions were taking place at first 5-15 min. Thermo-modification (50- 90 °C) has no significant effect on oil sorption. Making holes by punching nails (0.1 mm diameter) into EPS contributed to increases OSC to 2.538 g/g for 5 min sorption time (1 piece). Increasing the nails diameter to 1.65 mm resulted to increase in OSC to 3.280 g/g for 5 min sorption time (1 piece) and 7.998 g/g for 6 pieces. The results of investigation indicated that the oil sorption mechanism of EPS waste meanly adsorption with slow capillary action. Oleophilic action between EPS and oil is the mean force governing the oil adsorption into EPS. The use of EPS waste in oil spill cleanup will reduce pollution in two ways. Reducing the garbage and oil spill remediation.
Economics Of Steam Generation For Thermal EOR
Authors: Chaar Marwan , Venetos Milton , Dargin Justin , Palmer Daniel
Published: December 2014

The thermal EOR steam generation projects in Gulf oilfields are on such a large scale that they affect an entire country's economic position. As such, the policies related to oilfield steam generation should be decided at the national level using the cost of the marginal fuel. This paper calculates the steam cost for three methods: 1) once-through steam generator (OTSG) 2) once-through heat recovery steam generator (OT-HRSG) and 3) solar steam generator (SSG).

We have created detailed performance and economic models of the steam generation methods and used them to calculate the levelized cost of energy and the Fuel Break Even (FBE). We explore the environmental and economic burdens on the cost of steam generation. The effect of fuel price on the cost of steam is also analyzed with a focus on the marginal fuel price.

The analysis shows that the fully burdened steam costs using $6/MMBTU fuel, for OTSG, OT-HRSG, and SSG are $27/ton, $20/ton, and $17/ton, respectively. The FBE for SSG vs. OTSG is $4.95/MMBTU when the OTSG is unburdened and decreases to $2.25/MMBTU when the environmental burden of Carbon Cost is added. The FBE for SSG vs. OT-HRSG is $7.70/MMBTU when burdened with Power Opportunity Cost and $4.50/MMBTU when the additional burdens of Carbon Cost and Water Opportunity Cost are accounted for.

Finally, we analyze the limitations of OT-HRSG in an isolated oilfield where the electric:thermal demand necessitiates electricity-matched cogeneration. This limitation along with the steam cost at the marginal fuel price provides the decisionmaker with a steam supply curve.
The Hierarchy of Collaboration
Authors: Jakeman Simon , Al-Azawi Bahir , Alkarbi Ahmed
Published: December 2014

Collaborative Work Environments provide seamless communications between disciplines and between teams in different locations. Traditionally they have been used to connect staff in remote locations to teams in the headquarters, allowing real time monitoring of the health of the field, and fast decision making on operational issues and short to medium term optimisation opportunities. The ultimate goal is to be quickly alerted to events and make smarter, faster decisions using the key capabilities available to the company with access to all relevant knowledge, data and analytical tools required to reach a decision.

But this drive to make smarter, faster decisions is applicable to all levels of a company. In fact it becomes increasingly important as more complex decisions are required at higher levels, which can be influenced by interpreted data, personal opinions and perceptions.

To assist decision making at all levels ADCO and ADNOC are implementing a hierarchy of collaboration centres: The traditional asset based Collaboration Work Environments (CWE) will be responsible for the day-to-day management of the fields and ensuring delivery against the business plans.An ADCO Corporate Production Real Time Operations Centres (RTOC-P) will manage the production-related interfaces between the asset teams, the oil and gas customers and the shareholders. Through the interfaces between asset CWEs and the RTOC-P, technical experts positioned in the Head Office will also be able to provide technical support to the fields in critical areas such as rotating equipment.ADCO will implement a second Corporate RTOC with the specific purpose of managing and optimising ADCO's expanding drilling programme.At the highest level, ADNOC, as the main shareholder, will implement collaboration centres to interface with all operating companies, allowing ADNOC to provide more effective support in their evaluation and approval processes.

The key objective of making smarter, faster decisions applies at all levels.
Deficiency Management as Part of Asset Integrity - a Case Study
Authors: Ellis Eric
Published: December 2014

As part of the company's strategic plans, Oxy has implemented an asset integrity program across its global business units to ensure that surface equipment provides safe and reliable operation over its life cycle. This program involves static, rotating, power, and control equipment, and encompasses four major elements: mechanical integrity, maintenance, quality assurance/quality control, and corrosion management.

A case study involving a production water skim tank will be presented that highlights Oxy's deficiency management process, a key component within the mechanical integrity and maintenance elements. This tank, located in one of Oxy's production fields, suffered localized corrosion due to a design flaw that put the tank at risk of being removed from service after only 2 years of operation, with a significant impact to field production. The time line and sequence of events will be presented to show how Oxy's deficiency management process is used to support sound decision making regarding continued operation of assets with known anomalies or defects.

Attendees can use the content from this presentation as a reference for their asset integrity program or deficiency management process. While this case study is from an atmospheric storage tank, the deficiency management process applies to all equipment types and is an integral part of successful mechanical integrity and maintenance programs. This topic is directly related to Operational Excellence and HSE and is of value to established integrity programs as well as programs yet to be implemented. It highlights the full life cycle of deficiency management, including deficiency identification, engineering assessment (fitness for service), temporary/on-stream repairs, ongoing monitoring, and decision making regarding continued operation of affected equipment and facilities.

This case study shows how a successful outcome can be achieved through application of a robust deficiency management process, even with equipment that suffers premature damage due to design flaws (or unanticipated changes to operating conditions). Results from on-stream inspections and fitness for service evaluations will be shared as part of this presentation.
Laboratory Measurements on Changes in Carbonate Rock Properties due to CO2-Saturated Water Injection
Authors: Kono Fumio , Kato Ayato , Shimokawara Mai , Tsushima Kazuki
Published: December 2014

Carbon dioxide enhanced oil recovery (CO2-EOR) is gaining attention as a technique for reducing environmental impact and enhancing crude oil recovery. The injected CO2 reaches supercritical states at certain temperature and pressure conditions to be miscible with crude oil. Then, miscible CO2-oil mixture has lower viscosity and higher mobility than oil alone, leading to increased oil recovery rate. However, carbonate minerals are known to dissolve when CO2 is injected into reservoirs; therefore, it is important to evaluate how properties of rocks in a carbonate rock reservoir are affected by CO2-EOR. In this study, CO2-rich water was injected on carbonate rock samples mainly collected from Middle Eastern oil field and laboratory measurements including SEM image, liquid chromatography analysis, NMR T2 relaxation time and elastic wave velocity measurement, were conducted. The dissolution states of carbonate minerals were investigated by SEM images. Furthermore, liquid chromatography analysis was applied to CO2-rich water flooded through the samples to detect the amount of dissolved carbonate minerals. The porosity increase estimated from the chromatography analysis could be 0.6% or higher at 100 pore volumes (PV) injection. On the other hands, it was observed that samples became shorter as injection increased. The sample shortening may be caused by mechanical compaction associated with pressure loading test. The corresponding porosity reduction due to the sample shortening was estimated; magnitude of the average value of four sample is comparable to porosity increase due to chemical dissolution. Elastic wave velocity measurements showed P-wave velocity decreased in all the samples, as the amount of CO2-rich water increased; P-wave velocity increase at 100 PV was 2 - 10 %. S-wave velocity decrease was also observed to be 2 - 4% in the most of samples. Moreover, intensity reduction of small size pore was observed by NMR T2 relaxation time analysis. Thus, it was confirmed that effects of CO2-rich water injection on reservoir rock properties cannot be negligible.
Dynamic Modelling for Well Design, Increasing Operational Margins in Challenging Fields
Authors: Vielma W. E. , Mosti I.
Published: December 2014

The easy oil is gone and current field developments requires different approaches to produce oil and gas reserves in the most effective and economic ways, keeping the safety standards as high as technologically possible.

The use of dynamic hydraulic modelling software to predict and establish wellbore pressures and temperature in challenging wells (e.g.: narrow margin window, HPHT or mature/depleted reservoirs), enable Drilling Engineers (DE) to make the well design within the operational limits for drilling, tripping, casing and cementing operations, thus allowing access to reserves. However, this process must start with a management of change in the philosophy that still is being applied today in planning and operational procedures (steady state modelling).

This process starts with an in-depth review of the expected pore/fracture pressures, wellbore stability window and temperature profile along the well trajectory. The prediction of the operational window for each of the well sections will then be used to review the optimal mud weight including the dynamic ECD/ESD management and dynamic kick tolerance limitation for the proposed fluid, considering the operational transient effects on the well design. Subsequently, dynamic surge and swab and cementing calculations are included in the review to ensure that pore and fracture pressure limits are maintained during all operations. Bottomhole temperatures as well as surface temperatures can then be reviewed and predicted to ensure that downhole tools and other components can be used according to tool specifications.

A combination of drilling techniques combined with real time pore pressure predictions, dynamic modelling and online drilling systems supported by the powerful computational technologies available nowadays, will change the way we plan and work our challenging fields in the near future.

This paper will explore the fundamentals of the dynamic drilling modelling required during the well planning process, in addition to a brief description of "online drilling systems", to allow safe access to challenging fields.
Building Tomorrow's Safety Leaders - An Engaging Programme for Behavioural Change
Authors: Ross Gregory
Published: December 2014

To facilitate the vision of becoming The World's Most Admired Oil Service Company, Petrofac embarked on an engaging programme to cultivate the safety behaviours of its future leaders. Targeting the 2013 graduate intake to the company's prestigious graduate learning and development programme based in its Sharjah Academy headquarters, the safety programme aimed to focus on learning, innovation and action: Using learning to shape what we do and improve.Doing things differently (innovating) to be more effective.Demonstrating what we've learned and taking the lessons forward through action – changing our behaviours.

This paper describes the elements of the programme, why it was developed and how it was delivered. It is presented with source material and interactive ideas for others to model and utilize in their leadership programmes.

The programme was structured into two phases; establishing the Foundations and Readiness for Site, with the latter delivered six months later to consolidate the foundation elements prior to graduate engineers being mobilised to site.

Ideas were drawn from diverse sources such as TED Talks, Malcom Gladwell's The Tipping Point: How Little Things Can Make a Big Difference, Simon Sineck's Start With Why: How Great Leaders Inspire Everyone to Take Action, and W2 Training (who run safety leadership programmes for Petrofac).

Learning modules included: Leadership – introduction to Petrofac Leaders' Guide to Safe Operations, developed to provide thoughtful and structured advice on the behaviours to adopt for effective safety leadership.Culture - exploring the importance of organisational, cultural and behavioural aspects of safety management.Hazards, Tools and Rules – worksite hazards and risk assessment processes, HSSE tools, Petrofac's Golden Rules of Safety, and a simple model for effective intervention at site.

A case study pulls together the programme elements through review of a major accident.

The programme concludes with a call to action through the development of ‘Keystone Safety Habits’, with the hope these promote other aspects of the graduates' safety behaviours and build momentum to fuel transformative change in the company's safety culture.
Interactive Planning Tool for Integrated Activity Planning to Optimize Maintenance Activity Schedules to Minimize Production Losses Improve Forecast Quality
Authors: Said Saad A. , Al-Sheikh Medhat Ali , Al-Hadrami Hussein Amer , Al-Hamedi Kholoud Salem , Kirkman Matthew , Lasrado Vineet , Rodriguez Miguel , Habash Mahmoud
Published: December 2014

Production forecasting is an important business process requirement for operators to plan production operations, budgets, and future projects. Production forecasting can be performed over different time horizons—monthly, quarterly, yearly, and even longer-term over the life of the field. The tools used also depend on the time frame of the forecasting horizon. Activity planning or, more specifically, integrated activity/field planning is an equally important process that is tightly linked with the production forecasting. This is challenging for several reasons, such as the usage of different tools for planning and production forecasting, the lack of integration between the different systems, and disconnected business processes.

A major offshore operating company (ADMA-OPCO) operates two large fields with ongoing significant brownfield modifications, inspection, surveillance, and drilling activities that impact production. Planning and scheduling these activities, taking into account the production impact and helping to minimize production losses, is a complex task that requires coordination between multiple departments. The operating company recognized significant benefits could be achieved by using integrated activity/field planning to provide an understanding of the impact of activities on the production forecasts.

To achieve this, and with support of the planning group, the operating company developed an application to enable rapid visualization of the production impact resulting from the interaction of all field activities, targeting the following objectives: 1) enhance the accuracy and confidence of Field Sustainable Production Rate (FSPR) estimates and production forecasts, 2) enable workflow consistency and process efficiency, and 3) enable the realization of improved operational efficiencies and FSPRs. This application was developed as a pilot project, working in partnership with a service company. The pilot is now moving ahead to implementation so that end users can begin working with the system to help optimize activities and minimize production downtime. There are plans to further enhance the system by integrating it with engineering/simulation models. Such integration will provide the added benefit of reducing the forecasting horizon over which the system can be used and will be closely linked with production optimization.
New Method of Analyzing Cost Estimation by Integrating Monte-Carlo Simulation and Market Investigation
Authors: Li D. , Jin F. , Yin Y.
Published: December 2014

New method of analyzing cost estimation by integrating Monte-Carlo simulation and market investigation is proposed to consider both the uncertainties of cost estimate and their market drivers. Critical items which have big impact on cost estimation will be selected based on sensitivity analysis of Monte-Carlo simulation. By Likert scale, Relative Important Indices (RII) and Normalized Important Indices (NII), important critical items will be chosen from critical items based on both discipline experts' experience and procurement experts' experience. Important critical items will be re-enquired in details in the market. Eventually, the re-rankings of market drivers will be acted as guidelines for carrying out project cost re-simulation with inquired information of important critical items more efficiency. As one case, one petrochemical EPC contracting project in Saudi is illustrated to verify the validity of proposed method in practice. On the basis of the traditional cost risk analysis by Monte-Carlo simulation, the methodology of analyzing project cost estimates by integrating market-drivers, Monte-Carlo simulation and the Likert scale are proposed and obtain the following conclusions: (1) re-ranking of cost items are obtained by integrating sensitivity analysis of Monte-Carlo simulation with Likert scale in order to re-enquiry the prices of important critical items for adjusting cost estimates; (2) identifying market drivers affecting cost items and obtaining the re-ranking of market drivers for project management team to take effective and rational measures.
Specific Workflow for Integrated and Multiscale Geoscience & Reservoir Evaluation Dedicated to Middle East Carbonate Reservoirs
Authors: Javaux C. , Chenot D.
Published: December 2014

This paper explores some of the most innovative building blocks of the 3D modeling workflow used in carbonate reservoirs to deal with their natural complexity. Based on real published cases, different methodologies are presented.

Stratigraphic forward modeling can capture specific carbonate geometries, i.e. clinoforms, rudistid build-ups, incisions, tidal channels of Shuaiba and Mishrif platforms, and help predicting subtle traps. The role of 3D seismic, specifically through stochastic impedance inversion is highlighted to detect depositional heterogeneities in the Mishrif.

Another Mishrif example shows porosity prediction from post-stack impedance inversion and feedback loops between synthetic versus original seismic data and between synthetic seismic versus the reservoir model. Recent breakthrough is achieved with a 4D seismic pilot acquired over a carbonate field with a long producing history. 2G&R interpretation (including fluid and dynamic constraints) integrates 4D in-house warping processing.

Then the paper focuses on the tracking of dolomitic bodies, such as in the Khuff or the Arab formations. It is first based on the identification of their origin at wells, by petrography, geochemistry and sedimentology. Dolomitic bodies are then propagated in 3D with the constraint of seismic data. Probability cubes of dolostones versus limestones are derived from classification of multi-realization stochastic impedance inversion. These cubes are directly compatible with the geomodel grid. The spatial and petrophysical distribution of the early to late dolomitic overprints can be simulated with process-based and object-based methods.

This paper ends with a comprehensive 2G&R integration capturing heterogeneities which impact the development plan. The complex faulted Cretaceous reservoir taken as example has large matrix permeability contrasts linked to facies and diagenesis and is baffled by continuous dense zones and tar mats. To avoid any time-consuming numerical upscaling between geological and simulation grids, the same grid was built for the two models allowing quick feedback iterations during the history matching and further model updates.

Thanks to high performance (HPC) computing technology, new simulation opportunity opens the floor to Giga cell dynamic models at very fine resolution. These HPC based simulations are well adapted to the Middle East giant carbonate fields.
Risk Evaluation of a Simplified Approach to Reservoir Performance and Management in a Complex Field: Revisiting the Limits
Authors: Khan M. N. , Ouzzane D. E. , Menchaca T. Felix
Published: December 2014

Generally the hydrocarbon recovery factor and the complexity of the recovery mechanism are directly related. With the maturation of a producing field, enhanced monitoring plans and the implementation of fit-for-purpose data analyses workflows become necessary to understand well and reservoir dynamics for adequate reservoir management decisions. However, in reality, shifting the paradigm to adopt appropriate work strategies can, in certain circumstances, be restrained by several factors, including organizational issues.

In this paper, the risk of implementing simplified reservoir management practices in a complex carbonate field is evaluated. An extensive study carried out in a thin oil-rim carbonate reservoir which undergoes substantial gas and water injection in its huge gas cap and aquifer respectively. The objective of the study is to review the use of conventional lift curves i.e., oil rate – well head pressure cross plot, to:

Predict well performance changes under varying production conditions. Accurately allocate daily well production.

It is found that the use of a simplified approach for well performance analyses and production allocation may not be representative in this particular case. The potential risks of using simplified approach are identified and the need of adopting sophisticated processes, to carry out appropriate modelling for representative results, are also discussed in this work.

This study conceptually demonstrates that a fully integrated reservoir/well/network coupled model is required to accurately address such cases. An integrated approach would not only benefit better understanding of well and reservoir behavior, but it would also aid meaningful decisions for establishing reservoir management best practices and strategies.