In Abu Dhabi fields, strike slip faults can be originated from deep seated basement and/or reactivated salt related faults in a wrench tectonic regime. This paper outlines the identification of strike slip faults using 3D seismic imaging and describes the characteristics, orientations, spacing of the fault zones and the characterization of fault corridors through horizontal wells. Finally comparing similarities and contrast in the faults systems between different fields at the seismic scale.
The structural development and deformation mechanics associated with the Late Cretaceous tectonic phase represent the key factors of hydrocarbon accumulation in Abu Dhabi, where strike slip fault system that forms structural traps with several discoveries have been made.
3D seismic analysis has been performed on multiple 3D seismic cubes, and structure sensitive seismic attributes at different stratigraphic levels has been derived to better understand structural characterization and the geometry of Strike Slip systems. The main NW-SE fault system consists of a complex series of sub-parallel faults that connect via transfers, relay ramps or accommodation zones. Seismic images shows that these zones are associated with micro faults, fractures and folded closures resulting from the development of positive and negative flower structure.
These deep-seated faulting generally drives strike-slip tectonics happened when basement faults are reactivated a zone of rotational bulk strain develops in the overburden. The strain is accommodated by a variety of en-échelon structures including Riedel shears, normal and thrusts faults and folds. However, in deep seated detached salt related tectonics, a symmetric, conjugate pair of strike-slip faults will develop accommodating rotational bulk strain
The development of Lower Cretaceous reservoirs in a mature field located 84 km southwest of Abu Dhabi required a series of stress measurements across the reservoirs to tectonically calibrate the 3D Geomechanical model. The stress measurements were acquired by multiple straddle packer microfrac tests conducted through pipe-conveyance in a slim openhole wellbore. Various pore pressure depletion conditions across the reservoirs make the deployment of straddle packer tools in slimholes a very challenging operation.
Five in-situ stress measurements are acquired in this study from the proper identification of fracture closure pressure after reaching the formation breakdown pressure. Each microfrac test consists of three pressurization cycles and three pressure decline (fall-off) periods after fracture propagation. The fracture closure identification is achieved using three different pressure decline analysis methods on each fall-off test: (i) square-root of time, (ii) G-function and (iii) Log-Log plot. The final fracture closure measurement is obtained after consolidating the three fracture closure identification results in all three injection cycles conducted on each microfrac station.
The Microfrac tests conducted in the vertical pilot borehole provide precise in-situ measurements of formation breakdown, fracture reopening, propagation and closure at multiple reservoir layers. These in-situ measurements provide an accurate present-day stress profile across the reservoirs for constructing a proper 3D geomechanical model of the field. These microfrac tests measure minimum horizontal stress gradients of approximately 0.66 to 0.76 psi/ft, confirming the normal faulting stress regime in these reservoirs. The tectonic stress calibration is obtained by adjusting the value of tectonic strains across the reservoirs until the log-derived minimum horizontal stress matches the fracture closure pressure from the microfrac tests.
These in-situ stress measurements provide the subsurface information required to fully calibrate the tectonic stress acting on the reservoirs. This tectonic stress calibration is needed to create a representative 3D geomechanical subsurface model to predict accurate subsurface responses to stress and fluid flow over the field development. Additionally, conducting microfrac tests in slimholes provides multiple acquisition benefits: the straddle packer tool tolerates higher differential pressure across the elements than in large borehole, achieving higher absolute bottom hole pressure to induce formation breakdown; the borehole induced stress zone is radially smaller compared to larger hole sizes; the induced fracture does not required excessive propagation away from the borehole in order to capture the far-field in-situ closure stress.
Abu Dhabi Company for Onshore Petroleum Operations (ADCO) manages all oil production reservoirs in all of its assets. Through ADCO's commitment to improvement, efficiency, and excellence, a new technology in the form of an Oil Producer Tie-in Modular Skid is being considered. The concept of the Tie-in Modular Skid is to integrate all wellhead tie-in and completion facilities into a single modular skid ready for field installment. Such wellhead facilities include: well head control panel (WHCP), SCADA RTU (telecommunications), chemical injection, solar panels, interconnected piping, field protection and safety equipment (SSV/ HIPPS), F&G detection, and finally a manual choke valve. The purpose of implementing this technology is to maximize production time by minimizing the tie-in period of conventional off pad oil producer wells, as well as maintain the high HSE standards associated with the wellhead area.
Safety, as always, remains the top priority in all of ADCO's processes; both surface safety valves (SSVs), making up the HIPPS, will maintain their location for the Christmas Tree's protection, while the flowline isolation valve will remain 100 meters away from the wellhead for the pipeline's safety. Accordingly, the Oil Producer Tie-in Modular Skid will be kept 80 meters away from the wellhead to allow for rig access during work overs without the necessary disassembly of all the piping and instrumentations as is the case in the current configuration or the business as usual (BAU). Moreover, the strategy deployed by ADCO for the integration of this production facility's technology is to free issue the critical items (WHCP, mechanical valves, SSVs, chokes, etc.) to the tie-in contractor whereas the bulk material will be included in his or her scope. Furthermore, the tie-in contractor will be responsible for the fabrication, assembly, transportation, tie-in, pre-commissioning, and commissioning of the skid.
Upon the implementation of the Oil Producer Tie in Modular Skid many advantages and benefits can be enjoyed. The skid's robust design is advantageous for enhanced operability and maintainability. Additionally, the implementation of this technology will decrease the wellhead facility's footprint, construction activities and commissioning time, tie-in schedule, storing inventory, procurement services and price agreements, HSE risks during construction, field service preparation for workovers, and finally logistics/mobilization. Lastly, the skid offers the convenience of relocation upon the depletion of the well.
Shbair, Alaa F. (ADCO) | Al Hammadi, Hamdan (ADCO) | Martinez, John (ADCO) | Adeoye, Olanike (ADCO) | Abdou, Medhat (ADNOC) | Saputelli, Luigi (Frontender Corporation) | Bahrini, Fahmi (Frontender Corporation)
As reservoirs mature, subsurface flow complexity and surface production operation challenges increase. This brings the necessity of making capital-intensive decisions to sustain or increase reservoir potential in an optimum way. However, subsurface uncertainties affect decision success. Reservoir surveillance, a process that involves data acquisition, validation, analysis, integration opportunity generation and execution, can mitigate the outcome of such decisions in the presence of uncertainties. Although Value of Information (VOI) is a well-known process for justifying data acquisition, engineers struggle to extract the relevant information from historical data to apply Bayesian approach. The objective of this paper is to illustrate a methodology for identifying the value of information in reservoir management, in particular for deriving the conditional probabilities of success when new and imperfect data are acquired. A methodology to assess the value of reservoir surveillance is supported by two cases. In the first case, the incremental value of Real-Time Reservoir Characterization (RTRC) in underbalanced drilling (UBD) was nearly 100 times the cost of the services; in the second case, the incremental value of permananet downhole gauges (PDHG) was near 230 times the cost of installation and services. Reliability of facquired data, among other uncertainties, resulted to be a key success factor for both cases; however, in worst-case conditions, the incremental value was always positive.
The presence of Low Resistivity Pay (LRP) in reservoirs has been widely reported worldwide for both, clastic and calcareous formations. By definition, a LRP is not identified by the resistivity log, as its electrical beam is short circuited by the microporosity water bearing. This effect results in lower responses than expected for the conventional resistivity log, and hence, in higher estimations of water saturation that observed from production data. There are many factors that could create a LRP effect such as water invasion, conductive minerals, fracturing, thin bedding, fresh formation water or rock fabric (i.e. microporosity).
Regarding to rock fabric as driver for the LRP effect, the most common is the presence of the microporosity. This microporosity can be created by diagenetical processes (i.e. micritization) or whatever other component or process which preserves a microporous system inside the total porosity system of the rock. The presence of microporosity in the porous system, as a water bearing system, acts as an electrical shortcut for the electrical current, and it increases the general water content as calculated by the resistivity tool. The result is that SW due to microporosity contributes as Irreducible Water Saturation (SWirr) and not as Free Water Saturation (SW), with a direct effect on reserves assessment (Static Model), but with no significant effect to the field production (Dynamic Model).
The aim of this study is to identify the eventual presence of a LRP, and to determine its origin. By the above, a new fluid saturation assessment was performed based on both, available core and log data, together with a new set of core data focused on the available cored oil wells, in order to identify and recalculate the Gas, Oil and Water saturations for building a the new Static and Dynamic models. The new set of core analysis includes not only Conventional Core Analysis (CCAL), such as air porosity, grain density, Ka, Kk, Kg, CT Scanning or thin sections, but also Special Core Analysis (SCAL) as Mercury Injection Capillary Pressures (MICP) and Nuclear Magnetic Resonance (NMR).
The aim of this study is to propose a stratigraphic and sedimentary framework though the integration of available sedimentary, diagenetic and petrophysical data, which will be utilized in the construction of a high resolution stratigraphic framework, as an input into comprehensive review and update of an existing model of heterogeneous carbonate reservoir in a mature field in Abu Dhabi, UAE.
Depositional facies have been defined in cored wells, subsequently were associated taking into account the biologic and sedimentary processes in response of carbonate growing and sea level changes, allowing the identification of the main stratigraphic surfaces.
Surfaces can extend the correlation along the field and define the model of facies that, with the evidence provided by cores, can recreate and predict the different regressive-transgressive cycles in high resolution which the carbonate platform were undergone during its evolution.
Diagenetic evolution, interpreted through laboratory observations, was integrated with facies and petrophysical evaluation allowing the understanding of the spatial distribution of petrophysical properties within a heterogeneous reservoir and define a new set of facies which will be used in the generation of geological static model.
Application of sequence stratigraphy methods in cores, and extended in logs allowed the identification of six depositional sequences, with thicknesses of 2 to 4 meters each, corresponding to the phases of carbonate platform growth. Within each depositional sequences, typical cycles were defined that support the understanding in the association of facies and their relationship during the deposition.
The identification of sedimentological cycles not only genetically organizes the facies and predicts the stacking pattern, but also makes possible to find an excellent correspondence between cycles from lowstand system track intervals with good to excellent permeability values, and cycles from transgressive system track intervals with low permeabilities.
Many of the sequence stratigraphy published articles driven for the most important reservoirs along the Arabian Plate, provide an excellent tool in the regional correlation. However, they are not enough to be used in the reservoir characterization in detail that is required during the development of the field neither as input data in the generation of geological static models that use the sedimentary trends as constrain to populate the petrophysical properties.
The expansion in recent years of domestic oil and natural gas production has profound implications for the supply of energy in the twenty-first century. It has reignited calls for the nation to achieve "energy independence. There is no doubt a surge in the domestic natural gas production with tremendous opportunities. Driven by innovations in drilling and completion techniques, development of oil and natural gas reserves is one of the most rapidly growing trends in the world. Gas is used extensively for electricity generation and with the increasing demand, it is always a challenge to bridge the supply and demand gap.
Maximizing the daily gas production rates and ensuring continuous supply of gas to the downstream industry is critical for the economy.
Unlike crude oil, the biggest challenge in the gas production it that it cannot be stored in storage tanks. Also a huge infrastructure is required to transport this gas from the source to the required destination where it has to be processed for utilization.
Meanwhile carrying out the periodic preventive maintenance activities on the gas wells, production facilities, flow lines and various instrumentations is essential too. Furthermore, some downhole reservoir data is needed periodically for reservoir management purposes to estimate wells potentials. During all these routine maintenance or reservoir monitoring activities, wells and plants are shut-in which results in production or injection loss hence translating in an extensive loss of cash and revenue due to the wells or facilities unavailability.
This paper highlights the work progress and then the lessons learned during each step of the development of the software in order to meet and maximize the gas production demand considering all the hidden factors which are adversely affecting the overall production performance.
Ahmad, Mubashir (ADCO) | Mohamed, Ihab Nabil (ADCO) | Yousfi, Fawad Zain (ADCO) | Al Hajri, Zaher Hilal Hamdan (ADCO) | Al Zaabi, Saleem Salman (ADCO) | Nasr, Alaa Mohamed (ADCO) | Romdhane, Mourad ben (ADCO) | Albadi, Mohamed Mubarak (ADCO) | Al Badi, Fuad Shamekh (ADCO) | Shamlan, Abdulla Mubarak Bin (ADCO) | Al-Ahmed, Mohammed Hasan (ADCO)
The expansion in recent years in the oil and natural gas sector has a profound implication for the continuous supply of energy in the market. There is no doubt a surge in the domestic natural gas production with tremendous opportunities as gas is used extensively for electricity generation. With the increasing energy demand, it is always a challenge to bridge the supply and demand gap. The era of sweet shallow gas is fast depleting and hence developing local sour gas production having higher concentration of hydrogen sulphide (H2S) and carbon dioxide (CO2), which are toxic and corrosive is seen as the viable solution.
Currently, ADCO took up a project to study developing the sour gas reservoirs. The objective of the appraisal program was to gain valuable reservoir data including PVT samples to finalize the facilities and full field development plan including testing the reservoir in an area where seismic data indicated better quality sweet spots.
The appraisal program was carried out and the major challenges to drill, test and produce the highly sour HPHT (High Pressure, High Temperature) gas were identified and mitigated. The data from the previously drilled wells penetrating the sour Arab zone was used to drill in the sweet spots identified but additional data was required to reduce the remaining key uncertainties to firm up the Gas In place volumes as the final results were crucial for strategical decisions.
This paper highlights the work progress and then the lessons learned during each step of the operation with the proposed mitigation to safely and efficiently drill the appraisal wells in the Arab sour reservoir having 37% H2S and 10 % CO2.
The objective of this paper is to establish why it is favorable to prioritize happiness at work. The paper focuses on the means as well as the outcomes of establishing and cultivating a happiness culture. It also helps us in focusing on maintaining happiness at work due to intensified competition and economic uncertainties. Also, its guides us with maintaining happiness at work through different perspectives.
Organizations should focus on implementing a culture that takes into consideration the employees' happiness as well as the employees' satisfaction (Frederickson & Branigan, 2005). Management should create efficient communication systems and
Job autonomy is another factor that influences job happiness. Institutions with minimum external supervision through democratic leadership, and teamwork increase the self-motivation, and are translated in to happiness at work.
Job security is also a factor that influences happiness at work. The job with a longer duration is considered a job with better or higher security, and this enhances the employee's happiness at work (Fredrickson & Branigan, 2005).
Happiness at work is the chief cause of exemplary job performance. Employees who are happy at work deliver their best. This is mainly portrayed through the absenteeism from work which seems to be minimal among happy employees. A good number of institutions have a happiness human resource manager whose main duty is to ensure that the employees enjoy doing their work (Cropanzano & Wright, 2001)…
Notably, happiness at work ensures emotional stability among the employees. Emotional stability is principal to the employees' health since it ensures that they do not acquire diseases due to stress (Cropanzano & Wright, 2001). Finally, happiness at work influences employee turnover. To some extent, even the unhappy employees seem to conduct their jobs properly because they have no other alternative. Happy employees will often maintain their jobs since their experience at work is pleasant. Happiness at work saves excessive expenditure due to employee retention.
It is important for institutions to embrace the virtue of happiness at work. It enhances productivity as well as the employee's well-being. If possible, employers should create departments that focus on employee happiness, thereby raising employee satisfaction for the organization's benefit as well as the employee's well-being.
Most of the existing literature work focuses on the problems and barriers at job, while this paper is a unique set of knowledges which enlighten a totally different perspective of increasing efficiency and productivity at work through highlighting the element of Happiness or happy culture at work.
Yegin, Cengiz (Incendium Technologies LLC) | Temizel, Cenk (Aera Energy) | Yegin, Yagmur (Texas A&M University) | Sari, Mufrettin Murat (Texas A&M University) | Jia, Bao (University of Kansas) | Alklih, Mohamad Yousef (ADCO)
Hydraulic fracturing is an important method to recover shale oil and gas that has drastically increased U.S. energy production in recent decades. Shales are low permeability formations where natural resources are trapped, and require a well-planned hydraulic fracturing process and a highly developed fracturing (fracking) fluid for efficient oil/gas recovery. In this study, a pH-responsive solution synthesized by supramolecular assembly of maleic acid and an amino-amide in an aqueous media is described as a potential fracking fluid owing to its mobility control, proppant carrying and settling capacities. Previous investigations on this solution system had shown its large potential to replace displacement fluids in EOR due to pH-tunable and reversible viscosity behavior.
The main working mechanism is that; the initial viscosity of injected solution is kept at moderate/high values to easily transport proppants and easily inject the fluid; and then decreased when the solution reaches a position near fissures for settling of proppants. It has been reported by rheology tests of the developed fracking fluid, which consists of the supramolecular solution and proppants (silica sand), viscosity can be changed about 1600 times from pH 3.8 to pH 8.3 in a reversible fashion at only 2 wt.% concentration. On the other hand, sedimentation studies indicated that the sedimentation speed of the silica proppants decreased around five orders of magnitude from pH 4 to pH 8, again in a reversible way. Furthermore, experimental studies revealed that the developed supramolecular solutions have both reversible pH-responsive properties, and tolerance against high salinities and elevated temperatures. Another outstanding property of these supramolecular solutions is their self-healing feature which enables them to disassemble and reassemble upon exposure to extreme shear stresses, while polymer viscosifying agents the fracking fluids degrade and break up under similar conditions.
The supramolecular assembly system discussed in this study has a promising potential to become next-generation fracking fluids with its outstanding properties including but not limited to pH-sensitivity, reversible viscosity, high proppant transfer capacity, tolerance to high temperatures and salinity, self-healing behavior, environmental friendliness and sustainability.