Results
First Application of LWD High-Resolution Ultrasonic Imaging in an Unconventional Horizontal Well in the Najmah Formation: Case Study from Kuwait
Al-Naqeeb, Mohamed Nizar (Kuwait Oil Company) | Ghneej, Ali Faleh Abu (Kuwait Oil Company) | Al-Khabbaz, Mohammed (Kuwait Oil Company) | Abdulkarim, Anar (Halliburton)
Abstract The unconventional Jurassic Najmah carbonate-shale formation in northern Kuwait has been tested and found to be a prolific source rock as well as a producer of gas, condensate, and light oil in different wells. The flow-controlling system, given the very low porosity, is highly dependent on the presence of a natural fracture network. The Najmah kerogen member, formally known as the Najmah shale, is the source reservoir composed of highly organic-rich argillaceous and calcareous clay, represented by very high total gamma ray values associated with high uranium on spectral gamma ray logs. Average matrix porosity ranges from 2 to 6%, low permeability from 0.01 to 1.5 mD, and total organic content (TOC) from 7 to 12%. Identification and interpretation of fractures, bed boundaries, and borehole breakout from high-resolution images plays a crucial role in optimizing completion design. Using wireline has been a challenge in horizontal wells, making logging-while-drilling (LWD) acquisition preferable. The case study is from a horizontal exploration well drilled with a rotary steerable system combined with gamma ray and resistivity sensors in the Najmah formation of north Kuwait, where a multi-stage fracking completion was planned. The logging program also included density, neutron porosity, sonic, and high-resolution ultrasonic borehole imaging measurements. To minimize the risk of stuck events, it was decided to use LWD acquisition. Wells in the area are typically drilled in the minimum stress direction (SHmin) to cross natural fractures perpendicularly, to optimize fracking. However, surprisingly, most of the natural fractures were almost parallel to SHmin. Overall, high data quality was achieved, and the results exceeded the end data usersโ expectations. In total 96 natural fractures, 16 bed boundaries, and a few breakout intervals were interpreted within a measured-depth interval of 1,610 feet. Some of the fractures could be identified with high confidence on a 1:200 scale log. The new information about fracture orientation will be considered for future well design planning. The results were also used to facilitate the optimization of future field development and completion design. Further field analysis and studies are planned to be performed to confirm the interpreted results.
- Asia > Middle East > Kuwait (1.00)
- Asia > Middle East > UAE > Abu Dhabi Emirate > Abu Dhabi (0.15)
- Geology > Geological Subdiscipline (1.00)
- Geology > Rock Type > Sedimentary Rock > Clastic Rock > Mudrock > Shale (0.74)
- Geophysics > Borehole Geophysics (1.00)
- Geophysics > Seismic Surveying > Borehole Seismic Surveying (0.35)
- Asia > Middle East > Kuwait > Jahra Governorate > Arabian Basin > Widyan Basin > Abdalli Field (0.99)
- Asia > Middle East > Kuwait > Ahmadi Governorate > Arabian Basin > Widyan Basin > Tayarat Formation (0.99)
- Asia > Middle East > Kuwait > Ahmadi Governorate > Arabian Basin > Widyan Basin > Greater Burgan Field > Wara Formation (0.99)
- (8 more...)
Unearthing Hidden Treasures Beneath Our Feet: The Thrilling Journey of Recent Oil Field Discovery and Charting Future Opportunities, Onshore Abu Dhabi
Salahuddin, A. A. (ADNOC Onshore, Abu Dhabi, United Arab Emirates) | Al-Ghaferi, M. R. (ADNOC Onshore, Abu Dhabi, United Arab Emirates) | Khan, K. A. (ADNOC Onshore, Abu Dhabi, United Arab Emirates) | Warsito, E. (ADNOC Onshore, Abu Dhabi, United Arab Emirates) | Aljneibi, N. M. (ADNOC Onshore, Abu Dhabi, United Arab Emirates)
Abstract This paper presents a case study of the successful discovery of an appraisal well on a fault-bounded oil accumulation, carried out recently. The discovery was made adjacent to two big mature fields, highlighting the importance of careful geological and geophysical evaluation in identifying and targeting untapped potential hydrocarbon reserves. This paper also showcases the pre-drilled estimation of the probability of success (PoS) to properly evaluate the risk associated to the prospect and improve drilling success. The study involved a comprehensive and thorough evaluation of geological, geophysical, and petrophysical data to understand the complexities of the petroleum system elements of the prospect. A range of advanced geoscience techniques were utilized, including seismic interpretation, advanced seismic imaging, well log analysis, core analysis, structural analysis, basin modeling, and play fairway analysis to develop a detailed understanding of the petroleum system elements of the area. This enabled the identification of high-quality potential hydrocarbon accumulation target in the fault-bounded reservoir. The appraisal well was drilled vertically using the latest drilling technologies and advanced data acquisition programs that allowed for better understanding on the reservoir characterization. The well intersected significant oil column thickness with good reservoir properties and the oil was of good quality. The discovery of the fault-bounded oil accumulation was a significant achievement, highlighting the analysis of drilling data, mud log, well logs, and production testing data to further understand the reservoir potential and productivity for field development plan purposes. The discovery also demonstrated and provided valuable insights into the importance of careful geological and geophysical evaluation in identifying and targeting potential hydrocarbon traps and reserves with same geological setting and trap concept in other onshore areas. The success of the appraisal well discovery on a fault-bounded oil accumulation demonstrates the importance of utilizing a range of advanced geoscience techniques to understand the complexities of the petroleum system elements of the prospect. This allows for the identification and targeting of potential hydrocarbon traps, and ultimately, the successful discovery of new reserves.
- Asia > Middle East > Saudi Arabia (1.00)
- Asia > Middle East > Yemen (0.93)
- Africa > Sudan (0.93)
- (4 more...)
- Phanerozoic > Mesozoic > Jurassic (1.00)
- Phanerozoic > Cenozoic (1.00)
- Phanerozoic > Mesozoic > Cretaceous (0.71)
- Geology > Structural Geology > Tectonics (1.00)
- Geology > Structural Geology > Fault (1.00)
- Geology > Rock Type > Sedimentary Rock (1.00)
- Geology > Geological Subdiscipline > Economic Geology > Petroleum Geology (0.79)
- Geophysics > Borehole Geophysics (1.00)
- Geophysics > Seismic Surveying > Seismic Processing (0.48)
- Geophysics > Seismic Surveying > Seismic Interpretation (0.35)
- Asia > Middle East > UAE > Thamama Group > Shu'aiba Formation (0.99)
- Asia > Middle East > Saudi Arabia > Thamama Group > Habshan Formation (0.99)
- Asia > Middle East > Saudi Arabia > Arabian Gulf > Hanifa Formation (0.99)
- (5 more...)
- Reservoir Description and Dynamics > Reservoir Characterization > Seismic processing and interpretation (1.00)
- Reservoir Description and Dynamics > Reservoir Characterization > Geologic modeling (1.00)
- Reservoir Description and Dynamics > Reservoir Characterization > Exploration, development, structural geology (1.00)
- Reservoir Description and Dynamics > Formation Evaluation & Management > Open hole/cased hole log analysis (1.00)
The Vital Role of Advanced Cutting Analysis in Unconventional Reservoir Characterization
Fahmy, Mahmoud Fawzy (Kuwait Oil Company) | Nguyen, Kim Long (Kuwait Oil Company) | Dasma, Mohammed (Kuwait Oil Company) | Al-Mutairi, Nami (Kuwait Oil Company) | Al-Morakhi, Rasha (Kuwait Oil Company) | Alkandari, Abrar Yousef (Kuwait Oil Company) | Quttainah, Riyad (Kuwait Oil Company) | Ousididene, Karim (Excellence Logging) | Moustafa, Ahmed (Excellence Logging) | EL Masry, Mohab (Excellence Logging) | Magnier, Caroline (Excellence Logging) | Sharma, Sachin (Excellence Logging)
Abstract Advanced Cutting Analysis technique has been widely used in the industry to assist drilling operations as well as providing support in formation evaluation. Recently, alongside with the speedy development of Najmah Kerogen unconventional reservoir in Kuwait, the technique has demonstrated its vital role resulting in significant cost saving, and reliable measurements that could be used to replace other expensive evaluations from cores or open-hole logs. The Advanced Cutting Analysis was applied in Well-H drilled recently in Kra Al-Maru field, West Kuwait (Fig. 1) that comprised of different technologies: X-ray diffractometry (XRD) for mineralogy, X-ray fluorescence (XRF) for rock chemical composition, Total Organic Carbon (TOC) analysis, and Pyrolysis for source rock characterization. The XRD-XRF technology was popular in the industry, and it could be acquired from core or open-hole log data. In this study, XRD-XRF was conducted on cutting samples. In order to prove the efficiency of this technology applied on cuttings and its potential use as alternative method to support unconventional reservoir characterization in the future, the result was validated with elemental spectroscopy wireline logs. This paper presents the workflow used for analyzing and integrating multidisciplinary datasets in order to develop an alternative method for unconventional reservoir characterization that included the use of surface advanced cutting and fluid analysis. The aim is to: Reduce the uncertainty of production sustainability and proper well planning of the tight fractured carbonate unconventional reservoir. Build up alternative reservoir assessment model using advanced cuttings analysis in HPHT wells, slim hole, limited logging, etc. Evaluate mineralogical composition of the rock including the formation brittleness index, which helps on the post drilling fracturing strategy. Elemental Gamma Ray as cost effective for geo-monitoring and well placement assistance as well as eliminate the risk associated to down hole effects such as: hole geometry, vibration, high mud weight used while drilling, rock mechanical stress, high temperature and pressure can lead to lost signal.
- North America > United States > Texas (1.00)
- Asia > Middle East > Kuwait > Jafra Governorate (0.25)
- Asia > Middle East > UAE > Abu Dhabi Emirate > Abu Dhabi (0.15)
- Geology > Geological Subdiscipline > Geochemistry (1.00)
- Geology > Rock Type > Sedimentary Rock > Clastic Rock > Mudrock (0.95)
- North America > United States > Texas > Permian Basin > Yeso Formation (0.99)
- North America > United States > Texas > Permian Basin > Yates Formation (0.99)
- North America > United States > Texas > Permian Basin > Wolfcamp Formation (0.99)
- (24 more...)
- Reservoir Description and Dynamics > Unconventional and Complex Reservoirs (1.00)
- Reservoir Description and Dynamics > Reservoir Characterization > Exploration, development, structural geology (1.00)
- Reservoir Description and Dynamics > Formation Evaluation & Management > Open hole/cased hole log analysis (1.00)
- (3 more...)
- Information Technology > Artificial Intelligence (0.68)
- Information Technology > Data Science (0.46)
Maximizing the Value of NMR Logging while Drilling, a Combination of Laboratory Measurements and Well Log Data concept.
Serry, Amr Mohamed (ADNOC Offshore) | Yousif, Sharifa Yousif (ADNOC Offshore) | Budebes, Sultan Ahmed (ADNOC Offshore) | Zakaria, Hasan Mohamed (ADNOC Offshore) | Efara, Mohamed Saher (Petricore- Khalifa University)
Abstract The application of segmented, smart completion strings is expanding to enhance the hydrocarbons production along extended horizontal drains that are drilled across heterogeneous carbonate reservoir units, Offshore Abu Dhabi. Conclusive formation evaluation answers are required to support the well completion design. Nuclear Magnetic Resonance well logging while drilling "NMR-WD" supports the operations efficiency, HSE and adds a wealth of input to the completion design in a time-efficient process. A quantitative matrix independent porosity and permeability are required. In this case, we present the value of laboratory NMR measurements to maximize the value of the log interpretation process, adding a conclusive picture of the pore size distribution and reservoir quality as critical inputs. Representative core plug samples of the different major rock types have been selected along the Upper Jurassic Carbonate sequence, Offshore Abu Dhabi. The plugs have undergone Soxhlet cleaning, and routine core analysis measurements before Mercury injection capillary pressure measurements were carried out on plug trims too. Saturation of the plugs was conducted using synthetic formation brine and desaturation has been conducted over porous plate. A complete scanning of the pore size and pore throat distributions was made available and the transverse relaxation time T2 cutoff for the irreducible fluid was identified, then applied to the NMR-WD dataset. The laboratory measurements could be used to reprocess the log data, bridge the gap between the Coates permeability computation and the offset core values based on the measured benchmark T2 cutoff values. The integration between the porous plate, MICP and NMR laboratory measurements is utilized to qualify the NMR-WD as a vital tool for the future similar formation evaluation operations across the same target reservoir. NMR-WD log data interpretation is enforced with a representative pore size distribution. The quantitative matrix properties representation improves the well completion design.
- Asia > Middle East > Kuwait > Jahra Governorate > Arabian Basin > Widyan Basin > North Kuwait Jurassic (NKJ) Fields > Marrat Formation > Upper Marrat Formation (0.98)
- Asia > Middle East > Kuwait > Jahra Governorate > Arabian Basin > Widyan Basin > North Kuwait Jurassic (NKJ) Fields > Marrat Formation > Sargelu Formation (0.98)
- Reservoir Description and Dynamics > Formation Evaluation & Management > Open hole/cased hole log analysis (1.00)
- Reservoir Description and Dynamics > Formation Evaluation & Management > Core analysis (1.00)
Abstract A practical example of a theory-guided data science case study is presented to evaluate the potential of the Diyab formation, an Upper Jurassic interval, source rock of some of the largest reservoirs in the Arabian Peninsula. A workflow base on a three-step approach combining the physics of logging tool response and a probabilistic machine-learning algorithm was undertaken to evaluate four wells of the prospect. At first, a core-calibrated multi-mineral model was established on a concept well for which an extensive suite of logs and core measurements had been acquired. To transfer the knowledge gained from the latter physics-driven interpretation onto the other data-scarce wells, the relationship between the output rock and fluid volumes and their input log responses was then learned by means of a Gaussian Process Regression (GPR). Finally, once trained on the key well, the latter probabilistic algorithm was deployed on the three remaining wells to predict reservoir properties, quantify resource potential and estimate volumetric-related uncertainties. The physics-informed machine-learning approach introduced in this work was found to provide results which matches with the majority of the available core data, while discrepancies could generally be explained by the occurrence of laminations which thickness are under the resolution of nuclear logs. Overall, the GPR approach seems to enable an efficient transfer of knowledge from data-rich key wells to other data-scarce wells. As opposed to a more conventional formation evaluation process which is carried out more independently from the key well, the present approach ensures that the final petrophysical interpretation reflects and benefits from the insights and the physics-driven coherency achieved at key well location.
- Geology > Rock Type > Sedimentary Rock (0.50)
- Geology > Geological Subdiscipline > Geochemistry (0.48)
- Asia > Middle East > UAE > Abu Dhabi > Arabian Gulf > Rub' al Khali Basin > Diyab Formation (0.99)
- Asia > Middle East > Saudi Arabia > Eastern Province > Arabian Basin > Jafurah Basin > Tuwaiq Mountain Formation (0.89)
- Asia > Middle East > Saudi Arabia > Arabian Gulf > Hanifa Formation (0.89)
- Reservoir Description and Dynamics > Reservoir Characterization (1.00)
- Reservoir Description and Dynamics > Formation Evaluation & Management > Open hole/cased hole log analysis (1.00)
- Data Science & Engineering Analytics > Information Management and Systems > Artificial intelligence (1.00)
A Success Story of Critical Data Gathering During the Development Phase of Extreme ERD Well Drilling
Anurag, Atul Kumar (ADNOC Offshore) | Alkatheeri, Adel (ADNOC Offshore) | Sainz, Alvaro (ADNOC Offshore) | Javid, Khalid (ADNOC Offshore) | Liu, Yaxin (ADNOC Offshore) | Al-Ali, Ahmed (ADNOC Offshore) | Telang, Viraj Nitin (Baker Hughes) | Indulkar, Kshudiram (Baker Hughes) | Kieduppatum, Piyanuch (Baker Hughes) | Thar, Hiten Pankajkumar (Baker Hughes)
Abstract This paper discusses a holistic combination of advanced formation evaluation techniques with pressure testing and reservoir navigation services to mitigate uncertainty related challenges in real time and successfully drill & place ERD laterals targeting Jurassic carbonate reservoirs. A meticulously planned approach to navigate the well trajectory by tracking the desired properties, informed decision-making while drilling and accurate data acquisition for aiding appropriate selection and placement in-flow control device (ICD) in lower completion design and future reservoir management contributed to the success of these complex wells in carbonate reservoirs. The first well in this study, involved drilling and evaluating a long lateral section as single oil producer targeting a carbonate reservoir. While no tar presence was expected, a combination of density, neutron porosity and nuclear magnetic resonance (NMR) logs while drilling resulted in identifying a deficit NMR porosity when compared to density porosity. Deployment of a formation pressure testing while drilling (FPWD) tool enabled measurement of the formation mobility and validate the presence of a tar. Using the same combination of measurements in the subsequent wells for delineating the tar enabled accurate planning of injection wells on the periphery of the field. Approximately 3 days were saved compared to the first well where the drill string had to be POOH to run-in with FPWD service. Hence, having FPWD tool in the same string helped in confirming the formation mobility in real time to call for critical decision making like changing the well trajectory or calling an early TD. Across all the wells drilled in this field, the formation pressure, mobility and porosity measurements provided valuable input for optimum ICD placement and design. Successful identification of unexpected tar resulted in substantial rig time savings, accurate planning of asset utilization and added confidence in design and placement of lower completions by utilizing LWD data. Benefits of integrated data and services combination became clear for applications involving advanced reservoir characterization and enhanced well placement in complex carbonate reservoirs. From the offset wells, a tar was seen in deeper formations but the integration of LWD NMR and mobility data from this well confirmed the presence of a tar within the zone of interest. The study established a cost-effective workflow for mitigating uncertainties related to tar encountered while drilling extreme ERD laterals in an offshore environment where any lost time results in significant increase in expenditures during the development phase. A systematic approach to tackle these uncertainties along with acquisition of critical data for the design & placement of completion results in optimum production from the reserves.
- Asia > Middle East > Kuwait > Jahra Governorate > Arabian Basin > Widyan Basin > North Kuwait Jurassic (NKJ) Fields > Marrat Formation > Upper Marrat Formation (0.98)
- Asia > Middle East > Kuwait > Jahra Governorate > Arabian Basin > Widyan Basin > North Kuwait Jurassic (NKJ) Fields > Marrat Formation > Sargelu Formation (0.98)
- Well Drilling > Drilling Operations > Directional drilling (1.00)
- Reservoir Description and Dynamics > Formation Evaluation & Management > Open hole/cased hole log analysis (1.00)
- Data Science & Engineering Analytics > Information Management and Systems (1.00)
Piloting the 1st Well-Test-Logging in the Middle East, Paving the Way to Low-Cost Dynamic Reservoir Characterization and Well Value Optimization
Nguyen, Raymond (ADNOC Offshore) | Jacques, Antoine (TotalEnergies) | Jaffrezic, Vincent (TotalEnergies) | Bigno, Yann (ADNOC Offshore) | Serry, Amr Mohamed (ADNOC Offshore) | Zakaria, Hasan (ADNOC Offshore) | Khan, Owais Ameer (ADNOC Offshore) | Jadallah, Omar (ADNOC Offshore) | Brouard, Benoit (Brouard Consulting SAS)
Abstract The development of carbonate reservoirs of a giant field, Offshore Abu Dhabi, requires long horizontal wells to maximize productivity, but at the risk of unwanted gas and water channeling through its inherent heterogeneities. Conformance can be enhanced with dedicated segmented completions (blank sections, Inflow Control Device, Autonomous Inflow Control Device, etc.) or selective acid stimulation (diverter, Limited Entry Liner), which are increasingly implemented to extend well life, and eventually well value. If these technologies have matured, success depends heavily on the quality of the formation knowledge prior to completion. As of today, conventional logs provide the basic ground, but they lack dynamic information, whereas production logging results are obtained too late, when the well is already completed. Initially introduced for the optimization of unconventional well completions (see Jacques et al, URTEC 2019), the Well Testing Logging (WTLog) offers the advantage to record a log of mobility, at the end of drilling the openhole, enabling a favorable timing to influence adapted completion and stimulation design. Contrasted viscosity brines are sequentially circulated through the drill pipes at a constant rate and back-produced from the casing at constant pressure. The fluids interface travels in the drain from the TD to the casing shoe, and the measurement of the differential formation seepage is interpreted into an injectivity profile. Combined with rate fall-off phase analysis, permeability and skin logs are derived. Lasting a few hours and realized with conventional rig equipment (such as cement pumps, coriolis flowmeters, Managed Pressure Drilling system), it is a nonintrusive, safe, and ultimately low-cost operation. Forward, it can replace costly logging, when aimed at characterizing heterogeneities. Within a year, the two first WTLog pilots of the Middle East were successfully designed and carried out. They targeted two appraisal wells in distinct undeveloped reservoirs (Cretaceous and Upper Jurassic formations) which benefited from rich acquisition programs (Image log, Production log) to benchmark and qualify this technology. After an explanation of the technology principles, this paper describes the design, operations, and results of these pilots. It then focuses on the petrophysical consolidation of the matrix/fracture characterization. It concludes by sharing the learnings and offers insight to what extent it is a promising technology to be applied in Middle East carbonate reservoir developments.
- Europe (0.84)
- Asia > Middle East > UAE > Abu Dhabi Emirate > Abu Dhabi (0.25)
- Phanerozoic > Mesozoic > Jurassic (0.68)
- Phanerozoic > Mesozoic > Cretaceous (0.49)
- Geology > Rock Type > Sedimentary Rock > Carbonate Rock (0.93)
- Geology > Geological Subdiscipline (0.66)
- Africa > Tanzania > Indian Ocean > K Formation (0.99)
- Asia > Middle East > Kuwait > Jahra Governorate > Arabian Basin > Widyan Basin > North Kuwait Jurassic (NKJ) Fields > Marrat Formation > Upper Marrat Formation (0.93)
- Asia > Middle East > Kuwait > Jahra Governorate > Arabian Basin > Widyan Basin > North Kuwait Jurassic (NKJ) Fields > Marrat Formation > Sargelu Formation (0.93)
Reduced Well Construction Time with Accurate Geostopping in Harsh Drilling Conditions: Case Study from Kuwait
Saleh, Khaled (Kuwait Oil Company) | Al-Khudari, Abdulaziz Bader (Kuwait Oil Company) | Al-Najdi, Amer (Kuwait Oil Company) | Al-Azmi, Mejbel Saad (Kuwait Oil Company) | Al-Otaibi, Fahad Barrak (Kuwait Oil Company) | Joshi, Girija Kumar (Kuwait Oil Company) | Abdulkarim, Anar (Halliburton) | Farhi, Nadir (Halliburton) | Nouh, Walid (Halliburton) | Clarion, Benjamin (Halliburton)
Abstract Traditionally, 12.25-in. hole sections in the Jurassic formations were planned to be drilled with mud weight (MW) of 20 ppg and solids content of 45%. The planned drilling would use a rotary assembly from the Hith formation, crossing several zones in which mud losses or gains were likely. The casing would then be set in the thin shale base of the Gotnia formation. A minor inaccuracy in casing setting depth could often lead to well-control issues. Pore pressure drops severely below the shale base and requires a MW of 15 ppg. Passing this shale base can lead to severe losses and potential abandonment of the well. An anhydrite marker is located approximately 50 ft above the shale base. To reduce risk, the operator would normally drill to this marker at a rate of penetration (ROP) of 20-30 ft/hr, then decrease the ROP to 2 ft/hr. While slowly drilling the last part of the section, penetration would be stopped every few feet to circulate bottoms-up to receive samples confirming the shale base; this process requires an additional 24 hours of rig time. After reaching the casing point, the operator would pull out of the hole to pick up logging-while-drilling (LWD) tools to perform a wiping run. This logging, however, is frequently cancelled because of wellbore stability issues, resulting in the loss of important formation-evaluation data across this interval. A new solution has been developed, comprising drilling with a rotary assembly to the final anhydrite marker, then pulling the string out of hole to pick up LWD triple-combo and sonic tools, with a conventional gamma ray sensor placed only 6 ft from the bit. The remaining part of the section would then be drilled at 7-10 ft/hr until the gamma-ray tool detected the shale base, thereby determining the casing depth. In addition, it was planned to re-log the previously drilled interval. This solution prevented the well from potential abandonment and reduced drilling time. It also secured critical formation evaluation data for exploration and future field development. The engineered drilling solution was tried for the first time in these formation sequences within a harsh drilling and logging environment. The option of rotary steerable services with an at-bit GR sensor was not considered because of the high cost.
- Asia > Middle East > Kuwait (0.67)
- Asia > Middle East > UAE > Abu Dhabi Emirate > Abu Dhabi (0.15)
- Well Drilling > Drilling Operations (1.00)
- Well Drilling > Drilling Measurement, Data Acquisition and Automation > Logging while drilling (1.00)
- Well Drilling > Drilling Fluids and Materials > Drilling fluid management & disposal (1.00)
- Reservoir Description and Dynamics > Formation Evaluation & Management > Open hole/cased hole log analysis (1.00)
Three Rock-Typing Methods and Implementation as Part of the Reservoir Characterization and Uncertainty Assessment: An Example from the Arab Formation Upper Jurassic, Onshore Field United Arab Emirates
Rodriguez Gonzalez, Jose Gregorio (ADNOC Sour Gas) | Mohammed Al Blooshi, Farah (ADNOC Sour Gas) | Ahmed Al Teneiji, Moza (ADNOC Sour Gas) | Sahel Abdulla Mohammed Bin Ishaq, Wala (Occidental Oil & Gas International LLC)
Abstract The paper explores some rock-typing approaches to characterize the reservoir quality in the Arab formation in onshore field of the UAE. The analysis aims to capture the heterogeneity of the reservoir, lateral continuity and link to the sedimentary and diagenetic settings. The data base used were the core analysis (RCA and SCAL), slab and thin section description and well logs. That information was assembled/integrated employing different Rock-typing approaches defined. The main focus was in the upper section of the Arab Formation dominated by dolomitic limestone intercalated with anhydrites. In most of the cases, the precursor rock fabric was preserved or at least interpreted from the thin sections. However, the diagenesis was important enough to have a strong overprint on the rock-quality of the reservoir and needed to be considered. Being the data concentrated in the crest of the structure, the challenge was to link the rock-typing to pre-conditioned sedimentary setting that once defined, it is expected to be control the 3D distribution of the rock-types in the reservoir model. The approaches have in common two main stages, the 1D modeling (at well level) and the 3D extrapolation. It has been considered that in the 1D modeling, rock-type definition, goes in to three layers of analysis: cored, uncored wells and an integration layer. Basically, the 1D models (rock-typing approaches) were calibrated with the core data to be able to calculate the rock-types in the uncored wells. Three main approaches were used: (1) Lucia's (1995-2007), (2) PC-Types: FZI iso lines/classes or GHE (Cortez and Corbett, 2005) combined with MICP data families which it is called in this paper PC-Types; and (3) Lithotypes, based on the lithological description which represents a more genetic approach. Lucia's method explores the textural aspects of the rock and aims to translate it into a RFN class that links Poro/Perm transforms and SW estimations to the texture of the rock. The PC-Types on the other hand, based its rock-type classes according to the families of SW-height curves and pore throat distributions. If they are transform into J-functions, a derivation of PC-Types is then linked to porosity/permeability relationships (GHE-classes), in which case a correspondence analysis is performed between the PC-Types and the GHE classes. Finally, the Lithotypes explore the lithology classes identified in the core description, partitioned in different categories. They were extrapolated to the uncored wells using different multivariable techniques (e. i. NN and Cluster Analysis). Each Lithotype has a corresponding poro/perm model and SW estimation functions calibrated with MICP data. The final resulting rock-type models will use the poro/perm relationships and SW-H functions defined in 1D modeling stage. They represent scenarios that are carry on in the 3D modeling and uncertainty analysis. The link between the rock-types and conceptual sedimentary model will allow a more realistic extrapolation of the rock-types beyond well control leading to more consistent 3D rock-type models and as per as consequence a more robust 3D property models linked to them.
- Asia > Middle East > UAE > Arab Formation (0.99)
- Asia > Middle East > Qatar > Arabian Gulf > Rub' al Khali Basin > Idd El Shargi Field (0.99)
- Reservoir Description and Dynamics > Reservoir Characterization > Geologic modeling (1.00)
- Reservoir Description and Dynamics > Formation Evaluation & Management > Open hole/cased hole log analysis (1.00)
- Reservoir Description and Dynamics > Formation Evaluation & Management > Core analysis (1.00)
A Unique Use of New Generation Pulsed Neutron Tool Integrated with Advanced Production Logging to Evaluate Gas Production from an Oil Well: A Case Study from Offshore UAE
Al Afeefi, Baraka Said (Schlumberger) | Bong, Saudyano (Schlumberger) | Mustafa, Hammad (ADNOC Offshore) | Kuliyev, Myrat (ADNOC Offshore) | Chitre, Sunil (ADNOC Offshore) | Bazuhair, Ahmed Khalid (ADNOC Offshore) | Anurag, Atul Kumar (ADNOC Offshore) | Dasgupta, Suvodip (Schlumberger) | Sookram, Neil (Schlumberger) | Mosse, Laurent (Schlumberger)
Abstract In a green field located in offshore Abu Dhabi, a new well was drilled in an oil-bearing zone and was completed with slotted liner inside a 6-in horizontal drain hole. Abnormally high gas rates were reported during the surface production testing of this well. This paper highlights the unique use of a new pulsed neutron tool combined with an advanced production logging tool for assessment of the well performance and identification of the source of gas breakthrough. This combination of advanced technology tools with measurements from array flowmeters, optical gas holdup sensors, and a new generation pulsed-neutron tool was deployed in the well to provide reliable flow type, borehole, and formation measurements in a gas environment. A multidisciplinary approach involving production engineering, petrophysics, and well integrity was essential in diagnosing this unexpected issue of high gas production. An integration of the various results from production logging, the pulsed neutron measurements, and open-hole and cement log data has helped in confirming the source of the produced gas. The acquired production log (PL) data revealed gas entry from the top of the lower completion and no presence of free gas below that depth. The zonal contributions from the horizontal lateral quantified from the acquired data also helped in assessing the productivity of the reservoir. The pulsed neutron log (PNL) measurements were acquired in the second run, which then helped confirm the borehole fluid properties and to identify and quantify the formation fluids. Combining the PNL and PL data helped identify the gas entry point accurately. Based on the integrated data interpretation, it was confirmed that the gas could not originate from the reservoir being produced through the lower completion and that there must be gas channeling downward through channels in the cement behind the casing from a gas reservoir above the oil reservoir. The unique use of the advanced PNL data and its integration with other log data facilitated the successful identification of the gas source and quantified zonal contributions in a challenging logging environment.
- North America > United States (1.00)
- Asia > Middle East > UAE > Abu Dhabi Emirate > Abu Dhabi (0.35)
- Geology > Mineral (1.00)
- Geology > Rock Type > Sedimentary Rock (0.46)
- Geology > Sedimentary Geology > Depositional Environment (0.46)
- Asia > Middle East > UAE > Abu Dhabi > Arabian Gulf > Rub' al Khali Basin > Abu Dhabi Field (0.99)
- Asia > Middle East > Kuwait > Jahra Governorate > Arabian Basin > Widyan Basin > North Kuwait Jurassic (NKJ) Fields > Marrat Formation > Upper Marrat Formation (0.98)
- Asia > Middle East > Kuwait > Jahra Governorate > Arabian Basin > Widyan Basin > North Kuwait Jurassic (NKJ) Fields > Marrat Formation > Sargelu Formation (0.98)
- Reservoir Description and Dynamics > Formation Evaluation & Management > Open hole/cased hole log analysis (1.00)
- Production and Well Operations > Well & Reservoir Surveillance and Monitoring > Production logging (1.00)