In this work, spinel based zinc, nickel and zinc-nickel ferrites were synthesized and modified with oxidatively polymerized polyaniline-phosphate. The corrosion protection behavior of these polymer modified ferrites was investigated after formulating with acrylic primer and subsequent coating on carbon steel panels. Salt spray test revealed that among all the anticorrosion pigments, polyaniline modified zinc-nickel ferrites showed significantly improved anticorrosion properties. Incorporation of PANI modified zinc and nickel ferrites in the primer coatings also improved the anti-corrosion performance. Pure PANI coatings suffered from adhesion problems with the substrate, which were markedly improved when PANI layered ferrites were introduced in the coatings.
Copyright 2012, Society of Petroleum Engineers This paper was prepared for presentation at the SPE Middle East Health, Safety, Security, and Environment Conference and Exhibition held in Abu Dhabi, UAE, 2-4 April 2012. This paper was selected for presentation by an SPE program committee following review of information contained in an abstract submitted by the author(s). Contents of the paper have not been reviewed by the Society of Petroleum Engineers and are subject to correction by the author(s). The material does not necessarily reflect any position of the Society of Petroleum Engineers, its officers, or members. Electronic reproduction, distribution, or storage of any part of this paper without the written consent of the Society of Petroleum Engineers is prohibited.
Bachman, Henry (Schlumberger) | Rampurawala, Mansoor Ali (Schlumberger Oilfield Eastern Limited) | Valori, Andrea (Schlumberger Middle East SA.) | Ali, Farhan (Schlumberger Middle East SA.) | Nicot, Benjamin (Schlumberger) | Sangani, Pratik (Saudi Arabian Chevron PZ) | Denny, Tim (Saudi Arabian Chevron PZ) | Newton, Steve
Unconventional resources merit strong attention in the oilfield today. Great value is placed on understanding the amount and viscosity of the oil which in turn guides the production strategy. We demonstrate a workflow employed in Middle East carbonate reservoirs containing intermediate to heavy oil. The workflow combines dielectric and nuclear magnetic resonance (NMR) log data, and it is complemented by laboratory measurements. The applicable range of viscosities is tens to thousands of centipoises.
Integrating dielectric and NMR log data provides a more accurate determination of saturation and viscosity. The workflow does not require any change to the processing of the raw data and is simple to implement. We demonstrate the workflow using log data along with correlations from lab measurements on core and bulk fluids. The workflow solves three key challenges for heavy oil analysis.
The first challenge is the overlap of heavy oil and bound water NMR signals, compounded by a radial variation of saturations near the wellbore. Conveniently, the physics of dielectric and NMR measurement results in depths of investigation of 1 to 4 inches. Dielectric-based analysis provides the total water-filled porosity, which improves the NMR-based saturation and fluid characterization. The second challenge comes from the effect of restricted diffusion of water molecules in pores. We show that a restricted diffusion model is required to obtain accurate saturations and viscosity. The third challenge is the reduced NMR sensitivity to viscosity for heavy oil. Lab measurements on core and bulk oil samples provide the parameters required to link NMR to viscosity.
We describe a workflow based on dielectric and NMR log data for a more accurate determination of fluid saturations and oil viscosity. The workflow takes into account a) the combined dielectric and NMR data; b) the carbonate restricted diffusion effect inherent in the NMR response for carbonates; and c) laboratory validation and interpretation support using core plugs in wells where the dielectric data was not available. We use log data covering a range of heavy oil viscosities to demonstrate the workflow in four wells.
Mega projects development with major increase in the number of assets, facilities, infra-structures and new technologies additional to current existing running facilities, require numerous efforts to ensure organization readiness for these mega projects future operation and support, with least minimum impact on the running business. Therefore well organized, innovative and systematic approach must be established to manage these mega projects readiness from all perspectives, controlling expansion and interfaces across the company towards future operation requirements. This readiness approach should captures major key operation readiness elements, activities, internal interfaces among the company and external with stakeholders achieving operation readiness and ensuring operation experience to be embedded during project development. A Readiness Assurance Process was developed based on previous experience, best practices, lesson learnt and available guide lines, covering 16 main elements of operation readiness which are Operations, Maintenance, Integrity, HSE, Procurement, Inventory, Commissioning, Agreements, Logistics, Human Capital, Automation, Services, Drilling / Reservoir, Finance and Brown Field. This assurance process covers most of the activities across the company and requires heavy involvement of all business units and divisions within the company therefore the word "Integrated?? has been added to the title reflecting the reality. Each element of the Integrated Readiness Assurance Process (IRAP) is divided into sub-elements that have comprehensive list of activities, prerequisite documents and definite deliverables scheduled through the "Project Development Value Assurance Process??. Integrated Readiness assures the full readiness of the organization from all aspects to company management and shareholders and supports the requirements of the project development; also it will ensure operation disciplines involvement through the mega project life cycle through well-established methodology. Deployment success of the readiness process relies on well-structured deployment methodology through establishment of sub-committees across the company organization with clear roles and responsibilities, Sub-committees consists of accountable focal points having relevant experience and knowledge to ensure well comprehending the readiness requirements and assuring their commitment for implementation. Subcommittees' meets on quarterly basis to report the execution progress, and identify forthcoming activities, major achievement verses major challenges and any area of concern along with mitigation strategies to a steering committee on six monthly basis looking for their directives on strategic decisions. Maintaining the deployment success requires monitoring and control techniques that enable proactive approach and progress measurement through performance indicators and balance score cards.
Al-Farhan, Farhan A. (Kuwait Foreign Petroleum Exploration Co) | Gazi, Naz H. (Kuwait Oil Company) | Al-Humoud, Jamal (Kuwait Oil Company) | Tirkey, Naween (Kuwait Oil Company) | Haryono, Rafiq (Kuwait Oil Company)
Interference testing, although primitive in terms of its introduction and idea to the petroleum industry, still stands to this day as one of the most cost effective and efficient ways of confirming communication and evaluating reservoir properties between wells. Similarly, a pressure build-up is one of the most accurate ways of estimating dynamic reservoir parameters surrounding the well, providing that the shut-in of the well is allowable. On the other hand, a drawdown test is not usually recommended due to the instability of the flow rate, and hence, the uncertainty in the parameter estimation when analyzing the transient of the pressure drawdown. In this project, due to production constraints a drawdown test was run for the active horizontal well as a substitute to the pressure build-up. It was therefore decided to couple the drawdown test with an interference test so as highlight the subsurface uncertainties. In order to achieve these objectives, careful design and operational coordination between the different asset teams and contractors is crucial to obtain interpretable and useful data.
Water production was observed in some of the nearby wells, and therefore communication between the horizontal well and the surrounding wells needed to be verified. The main objective of this project was to evaluate the reservoir parameters and connectivity surrounding the important horizontal well. In this test, the horizontal well was the active well in a five well interference test. The results of the test indicated different pressure behaviors seen from the observation wells corresponding to the pulse created by the horizontal well. Communication was established in some of the wells, whereas, faults were also verified in the surrounding regions. In addition, the drawdown analysis of the horizontal well showed all the flow regimes that relate to a horizontal wells' signature as well as boundary behavior which coincide with the interference test results. The results of the drawdown analysis indicate the possibility and accuracy of conducting a pressure transient analysis using this method without being constrained with production objectives, and hence not shutting the well in.
Majority of Oil & Gas projects pass through phases such as Concept,Front-End Engineering and Design (FEED), Detailed Engineering, Procurement,Construction, Commissioning and Start-up. FEED phase scope generally covers thebasic design and engineering of the facilities, development of the layout,vendor inputs for major packages, HSE impact assessment and refines the costestimates of the conceptual design. The FEED cost estimates are used to obtainrequired management approvals and also serve as basis to review the proposal ofthe Engineering, Procurement & Construction (EPC) contractors. The FEEDdossier, which is a compilation of basic design and engineering documents, isprovided to the EPC contractor to serve as input data for further detailingduring the EPC phase and forms a part of contract documentation.
Historically, the EPC contractor scope included performing the detaileddesign and engineering based on the FEED documents and in case of any conflictsor changes in design philosophy, the issues were referred to FEED contractorfor resolution. FEED Contractor's scope encompassed providing processguarantees on the system design and corrective engineering whereverapplicable.
More recently, with the emergence of the FEED endorsement concept, a singlepoint responsibility is passed on to the EPC Contractor to be fully responsiblefor the delivery of the project, meeting all requirements and without anyinvolvement of the FEED contractor. EPC contractors are required to endorse theFEED at the time of bidding and take full responsibility of the projectincluding process guarantees, in addition to the normal warranties / guaranteesassociated with usual EPC project scope. This concept is quite advantageous interms of Owner's project execution strategy, however, brings additionalchallenges and responsibilities to the EPC Contractors.
In essence, the FEED Endorsement requires understanding of the completedesign concept and complete verification of design without any face to faceinteraction with Owner or the FEED contractor. It is worth noting that FEEDendorsement requires significant efforts for design verification and includesredoing many basic design activities such as process simulations, systemhydraulics and other calculations within a short period. Often, additionalrequirements get added to the project scope during tender clarifications / FEEDendorsement phase enlarging the original scope. Such requirements added throughthe tender bulletins are generally not engineered and sometimes are not evenaligned with FEED documents. Resolution of such issues during tendering stageoften remains inconclusive. Since Owners do not generally entertain"exceptions" to the scope of works during bidding stage, contractors have nooption except to take an appropriate risk and accordingly price theproject.
Owner project teams including Project Management Consultant (PMC) involvedduring FEED phase do not essentially continue to the bidding / EPC phase. Dueto this, the responses to the clarifications raised by EPC contractors aresometimes not consistent with FEED philosophy and are influenced by the new PMCteam approach.
Khedr, Osama Hamdy (Zakum Development Co.) | Al Marzouqi, Mohamed Abdulla (ZADCO) | Jackson, Alfred M. (Zakum Development Co.) | Ibrahim, Muhammad Nasir (Schlumberger Middle East SA.) | Akhtar, Muhammad Nadeem (Schlumberger Middle East SA.)
The first Maximum Reservoir Contact (MRC) wells for a major operating company offshore Abu Dhabi have been successfully designed and implemented. In this paper, the design, optimisation, piloting, field implementation, and post-job field data evaluation for the most critical well are discussed.
The re-development strategy for the company hinges on the move to an islands-based development concept. This concept dictates that a significant number of wells be extended reach, long horizontals to maximize reservoir contact and exposure. The increased reservoir exposure will translate proportionally to accrued production (or injection) benefits and value, balanced reservoir sweep, and maximizing recoveries.
Hundreds of these MRC wells will be ultimately needed, to maximize recovery and drive the field daily production output from the current level to an increase of at least fifty per cent. However the challenges of designing, drilling and completing these complex wells are new to the operating company.
The operator embarked on a program of drilling pilot wells with a view to establishing new learning and understanding, which translates into efficiently designing, deploying and operating these wells for the field re-development.
The paper shows the methodologies employed for one of these pilot wells, right from the concept stage through to the modelling, design and optimisation. It also shows how operational considerations were fed into the optimisation workflow, and how the resulting design was implemented in the field.
The obtained field measurements such as resistivity, fluid mobility, production logging, production rates were compared to the initial design and performance forecasts, and excellent conformance is demonstrated, further validating the robustness of the implemented designs.
The paper highlights the lessons learnt from this exercise, and also proposes a recommended methodology for approaching and adopting the design and implementation of advanced wells, within oil and gas producing assets.
El Gazar, Ashraf Lotfy (Abu Dhabi Co. Onshore Oil Opn.) | Ayoub, Mohammed Ramadan (Abu Dhabi Co. Onshore Oil Opn.) | Dawoud, Ahmed Mohamed (Abu Dhabi Co. Onshore Oil Opn.) | Arslan, Izzet (Abu Dhabi Co. Onshore Oil Opn.) | Bin Sumaidaa, Saleh Awadh (Abu Dhabi Co. Onshore Oil Opn.) | Basioni, Mahmoud (Abu Dhabi Company for Onshore Oil Operations (ADCO)) | El Mahdi, Ahmed
This paper presents a case study of developing a significant volume of oil rim with a large gas cap reservoir in Abu Dhabi-UAE.
The reservoir is a low relief heterogeneous carbonate located in a complex environment represented by natural and artificial islands in the surface, shallow and medium water marine areas. The reservoir rock properties showed lateral and vertical heterogeneities as well as variation in reservoir fluid properties.
The static and dynamic data were utilized to construct representative geological and dynamic models for the reservoir. The field development objective focused on producing the oil rim while maintaining the gas cap as long as possible to save the reservoir energy and benefit from the gas cap pressure support.
Five years production dynamic data were available from two oil producers in addition to well testing and MDT data during the appraisal phase "13 wells??. These data were used to quality control the initialization and history match phases.
The development options included pressure support using water injection, lean gas injection, miscible gas injection and miscible WAG injection. The predicted reservoir performance of the oil rim indicated considerable gas cusping from the gas cap in all the development options.
It was a challenge to reduce the amount of gas production from the gas cap in all the development options. A new development option was introduced to perform miscible gas / WAG injection underneath the gas cap accompanied with optimization of the wells and completion intervals locations for producers and injectors to minimize the gas cusping from the gas cap. This resulted in significant enhancement of minimizing gas cusping with minor impact of the recovery factor.
The development of the oil rim was suggested to be in phases focusing on the lowest uncertainty segment of the reservoir. This paper provides the methodology followed to guide the development plan to fill in the uncertainty gap by a detailed data acquisition and monitoring programs to better understand the reservoir behavior.
Jasem Al-Saeedi, Mohammed (Kuwait Oil Company) | Al Fayez, Fayez Abdulrahman (Kuwait Oil Company) | Rasheed Al Enezi, Dakhil (Kuwait Oil Company) | Al-Mudhaf, Mishary N. (Kuwait Oil Company) | Sounderrajan, Mahesh (Kuwait Oil Company) | Subash, Jaikumar (Kuwait Oil Company)
Drilling activities have increased in the State of Kuwait to enable the production of more gas from the Jurassic formations. The wells drilled to these prospects are challenging because of HPHT conditions, sour reservoir fluids and narrow drilling window.
Only vertical and deviated wells have been drilled to date, and in order to augment the production requirements horizontal wells were planned. For effective development of these reservoirs, horizontal well profiles were planned to increase the ability of the wells to access a permeable interconnected vertical fracture network which could result in high productivity and reserve recovery.
After detailed study, well SA-297 was selected as an appropriate candidate for a horizontal pilot project. In this pilot, the objective was to drill the first horizontal well through the Najmah reservoir in the North Kuwait fields. The project, being the first of its kind, posed many challenges. These included: drilling and casing 16?? hole at 60º well trajectory to 13,500 ft.; drilling the salt-anhydrite high pressure Gotnia at 60º inclination; drilling a slim pilot hole in the reservoir with K-formate WBM to facilitate positioning of the lateral; plug back this pilot hole and execution of a high DLS sidetrack just below 10 3/4" shoe; casing off formations with borehole stability concerns; drilling 6?? lateral hole by geo-steering; tubing plugging concerns during DST testing
Due to plugging of the tubing during testing, an intervention job was carried out with a workover rig to clear the tubing with coiled tubing in a live well and subsequently retrieve DST tools. This was a unique job carried out for the first time in Kuwait.
This paper will give details on the well construction, the complexities in the drilling operations and technical challenges faced while drilling the directional trajectory and in the special workover operations.
Edwards, John Ernest (Schlumberger) | Herrera, Adrian (Schlumberger) | Judd, Tobias Conrad (Schlumberger) | Kristensen, Morten Rode (Schlumberger Middle East SA.) | Al-Rashdi, Yaqoob Salem (Petroleum Development Oman) | Hindriks, Cornelius
A new method of stress testing with a wireline tool uses a drilled hole sealed with a compression pad to apply hydraulic pressure to the reservoir. Geomechanics modeling shows why this reduces the fracture initiation pressure and avoids intersecting the borehole with the induced fracture. The superposition of two induced stresses, mechanical and hydraulic, causes the tensile failure to initiate towards the end of the drilled hole as the hydraulic pressure is increased. The 9-mm-diameter hole is drilled from the center of the sealing compression pad to a depth of up to 15 cm. A fracture initiating some distance from the wellbore will be located part way through the near-wellbore perturbed stress field and will propagate away from the wellbore to the far field in the direction of reduced minimum stress. Reservoir simulation shows that the leakage rate of injected fluid around the compression pad is insignificant.
The first jobs using this technique are described, including procedures for passive tool orientation so that the drilled hole is aligned with the maximum horizontal stress. Information revealed about breakdown pressures in tight dolomite explained why drilling-induced fractures were affecting resistivity logs and well test interpretation. The current procedure for stress testing is the pumping of drilling mud between inflated packers. The new technique described here solves two problems associated with the inflated packer method. The pumped fluid volumes are much smaller, so clean fracture fluid from a sample chamber can be used instead of mud. And the system compressibility is reduced, so the pressure transients are more responsive to the formation.
The ability to induce a fracture in the formation with a pad tool using dedicated fluid with a low dead volume creates a new way of connecting to the reservoir, an alternative to connecting via the borehole wall surface. This large, undamaged contact area due to the induced fracture beyond the drilling-damaged zone will facilitate sampling low-permeability formations or high-viscosity oils.