Syofyan, Syofvas (ADNOC Onshore) | Latief, Agus Izudin (ADNOC Onshore) | Ahmed Al Amoudi, Mohsen (ADNOC Onshore) | Al-Shamsi, Saif (ADNOC Onshore) | Hassan Ali Bal Baheeth, Asma (ADNOC Onshore) | Nestyagin, Andrey (ADNOC Onshore) | Ali Al-Shabibi, Tariq (ADNOC Onshore) | Banihammad, Basma (ADNOC Onshore) | Dasgupta, Suvodip (Schlumberger) | Mosse, Laurent (Schlumberger) | Yaseen Albuali, Abdulla (Schlumberger)
Carbonate reservoirs introduce challenge in providing accurate water saturation from conventional Archie equation. One of the reasons is due to the variability of the Archie cementation factor "m" because of complex and tortuous nature of these heterogeneous carbonates.
The study was performed by integrating core and log data from advance measurements to understand the root cause and range of the variability and an attempt to link sedimentology and diagenetic facies to petrophysical groups.
The Study focused on a carbonate reservoir with complex pore network. The formation resistivity factor (FRF) measurements were conducted with high-resolution sampling on a selected well. Each of FRF plug has associated porosity, permeability, thin sections, MICP, NMR and high-resolution dual energy micro CT scan. The m value from FRF is then plotted along the porosity-permeability plot. The capillary pressure parameters (entry pressure, slope, inflexion points) were extracted from MICP and relationship is plotted against m. Diagenetic facies described from the thin sections is compared versus m.
Principal component analyses was conducted to identify factors relating to m. The uncertainty on water saturation associated to variable parameter m was assessed using Monte Carlo analysis on multiple wells.
An advanced multi-frequency dielectric logging tool was run on couple of wells to provide variable water-phase tortuosity (MN) measurement. Specific analysis was performed to extract the variable m value from the measurement over limited zones, which has been derived from core "m" measurements.
Several wells located on the flank of the reservoir below water level were evaluated. Dean stark measurements were performed on a well and used to validate the saturation calculation.
It is obvious that the evaluated reservoir has high degree of heterogeneity as indicated by complex pore network with multi modal pore system as shown by the thin sections, MICP and plug CT Scan.
A Lower Cretaceous reservoir in one of the Abu Dhabi onshore oilfields is the focus of this study aimed 1) to understand, predict and distribute the impact of diagenesis on the reservoir quality, and 2) to define the reservoir Static Rock Types (SRT). This will eventually help to define and predict the reservoir flow units to better frame strategies and choices for reservoir static and dynamic modelling, and to support the decision-making process for the oilfield business plan. A fully integrated geological-petrophysical approach was used to carry out the study. Nine geological facies are recognized in the reservoir and grouped in four main reservoir facies categories: 1) rudist-bearing facies, 2) grain-supported skeletal and Orbitolinid facies, 3) Bacinella/ Lithocodium-coral facies, and 4) mudstone-supported facies.
This course discusses the fundamental sand control considerations involved in completing a well and introduces the various sand control techniques commonly used across the industry, including standalone screens, gravel packs, high rate water packs and frac-packs. It requires only a basic understanding of oilfield operations and is intended for drilling, completion and production personnel with some sand control experience who are looking to gain a better understanding of each technique’s advantages, limitations and application window for use in their upcoming completions.
This seminar will teach participants how to identify, evaluate, and quantify risk and uncertainty in everyday oil and gas economic situations. It reviews the development of pragmatic tools, methods, and understandings for professionals that are applicable to companies of all sizes. The seminar also briefly reviews statistics, the relationship between risk and return, and hedging and future markets. Strategic thinking and planning are key elements in an organisation’s journey to maximise value to shareholders, customers, and employees. Through this workshop, attendees will go through the different processes involved in strategic planning including the elements of organisational SWOT, business scenario and options development, elaboration of strategic options and communication to stakeholders.
Decisions in E&P ventures are affected by Bias, Blindness, and Illusions (BBI) which permeate our analyses, interpretations and decisions. This one-day course examines the influence of these cognitive pitfalls and presents techniques that can be used to mitigate their impact. Bias refers to errors in thinking whereby interpretations and judgments are drawn in an illogical fashion. Blindness is the condition where we fail to see an unexpected event in plain sight. Illusions refer to misleading beliefs based on a false impression of reality.
Oke, M. (Abu Dhabi Company for Onshore Petroleum Operations Ltd) | Shin, K. (Abu Dhabi Company for Onshore Petroleum Operations Ltd) | Rosli, F. (Abu Dhabi Company for Onshore Petroleum Operations Ltd) | Buzdar, M. (Abu Dhabi Company for Onshore Petroleum Operations Ltd) | Dantla, V. B. (Abu Dhabi Company for Onshore Petroleum Operations Ltd) | Al Ali, I. A. (Abu Dhabi Company for Onshore Petroleum Operations Ltd) | Abdelaal, A. (Abu Dhabi Company for Onshore Petroleum Operations Ltd) | Hussain, A. (Abu Dhabi Company for Onshore Petroleum Operations Ltd) | Ali, M. (Abu Dhabi Company for Onshore Petroleum Operations Ltd) | Lardhi, B. (Abu Dhabi Company for Onshore Petroleum Operations Ltd)
This paper highlights 3D reconstruction of the paleo-topography of the depositional environment for a Lower Cretaceous carbonate formation onshore Abu Dhabi using 3D seismic and well data. The reconstruction was carried out for two reasons: (1) to understand underlying geologic causes for anomalous lateral variations in pressure, production performance, and logged reservoir properties in the field and (2) to delineate geologic trends away from well control in order to guide further decisions on field development and reservoir management options.
Present-day structure of the reservoir top is a high-relief elongated anticline that is open to neighboring giant oil fields. Known hydrocarbon contact is below structural spill-point between the field and its neighbors, however pressure and production data indicate that the field is isolated from its neighbors. No fault was seen on seismic separating the field from its neighbors, thus raising possibility of stratigraphic separation. Further, study on core samples indicated that reservoir quality is controlled by depositional facies and early diagenetic modifications thereof. Thus, reconstruction of paleo-structure was conceived as a means of understanding and delineating geologic drivers for lateral variations in reservoir quality.
The reconstruction process relied on an integrated approach: combining information from seismic, well logs, sedimentology, and well test results. Sedimentology studies gave information on expected morphology of depositional environment and controlling factors for reservoir quality; seismic interpretation of structure and stratigraphy at several levels provided basis to understand present-day field architecture and structural evolution through geologic time; reconstruction of three-dimensional structure at time of deposition was achieved by means of restorative velocity models to translate input mapped surfaces to their approximate original morphologies; results validation was achieved by subjecting study outputs to conformance tests with independent data from well logs, pressure tests, production performance, and seismic attributes trends.
After reconstruction carried out in this study, the present-day steep anticlinal structure at the target reservoir was translated to a gently dipping ramp with morphology that is consistent with interpreted environment of deposition from cores. Outputs were further validated by conformance of well data and seismic attribute trends with the paleo-structure. Anomalous lateral variations in reservoir properties measured in wells were found to be associated with possible tidal channels that were interpreted to have caused localized diagenetic changes. Thus, findings from the paleo-reconstruction study provided a geologically consistent framework to understand lateral variation in well results, and also provided basis to guide further field development and reservoir management decisions as intended at study inception.
Although outputs from the paleo-reconstruction process used in this study were deemed to have given good results, potential pitfalls in applying the method are herein noted.
Golenkin, Mikhail Yurievich (LUKOIL-Nizhnevolzhskneft, LLC) | Latypov, Artur Spartakovich (Schlumberger) | Shestov, Sergei Alexandrovich (Schlumberger) | Bulygin, Igor Alexandrovich (Schlumberger) | Khakmedov, Azat Meredovich (Schlumberger)
First Intelligent multilateral TAML5 wells on Filanovskogo Field is the great example of how new technologies help to optimize CAPEX, and, thanks to higher productivity index, achieve higher production rate. Multilateral well geometry combined with ability to monitor and control each leg separately helps to optimize flow patterns, prolongs well life and contributes to higher cumulative production. The paper focuses on well design, project execution and production results.
In order to achieve results, work was done in several phases: Choose well design which would optimize CAPEX and allow to reach production and recovery targets. Perform two trial jobs on existing mature field to learn technology and prove the concept. Use experience gained on trial jobs to optimize requirements, well design and procedures. Execute the job, control and manage execution to ensure compliance to the plan. Review first production results and estimate benefits obtained from project execution.
Choose well design which would optimize CAPEX and allow to reach production and recovery targets.
Perform two trial jobs on existing mature field to learn technology and prove the concept.
Use experience gained on trial jobs to optimize requirements, well design and procedures.
Execute the job, control and manage execution to ensure compliance to the plan.
Review first production results and estimate benefits obtained from project execution.
This paper describes all the steps focusing mainly on installation procedure, execution and production results review.
As a result of the work done, LUKOIL successfully installed two first intelligent TAML5 completions on Filanovskogo field and achieved
The paper describes introduction of complex intelligent multilateral well design on the field. This practical example can be used for future reference by drilling and production focused petroleum industry professionals to better understand benefits and limitations of existing technologies. Actual production result can also be used as a benchmark for field development planning.
Numerous oil and gas reservoirs in Kuwait are suffering from H2S contaminations. The H2S concentrations in the affected reservoirs vary significantly from low ppm ranges up to 40%. The H2S concentration levels are related to the generation processes. The high H2S concentrations observed in the Lower Jurassic reservoirs can be related to the TSR process. The dominant H2S generation process in the Upper Jurassic and Lower Cretaceous reservoirs is the thermal cracking of the organic sulphur compounds (OSC) occurring in the Najmah and Sargjelu source rocks. The H2S contaminations observed in the Cretaceous reservoirs show indications of multiple H2S sources. The bulk of the H2S in these reservoirs is generated in situ by the BSR process. In some fields clear indications for H2S migrated from deeper horizons e.g. via faults are observed.
H2S contaminations are also observed at the top site facilities at various stages of the production process. The source for those contaminations is only partly in the subsurface. In several cases a distinct increase of the H2S contaminations of the fluids on its way from the reservoir well to the processesing facilities is observed.
New sampling and analytical technologies tailored to the H2S problematic have been developed, which support the selection of the appropriate mitigation or remediation strategy. The utilization of modern low cost DNA sequencing technologies for the analysis of the bacteria and archea species provide essential information for the design of appropriate chemical cocktails for the mitigation.
Reservoir modeling and forecast technologies have been developed to predict the development of the H2S concentrations in a reservoir. However, for a reliable forecast - irrespective which modeling system or tool is applied - the understanding of the H2S generation process is essential. Furthermore good quality and reliable H2S measurements are mandatory for the history match.
The mitigation and remediation of H2S is a major cost factor in the field development and operations. Field souring i.e. the increase of the H2S concentration during field life is the worst case scenario, which could cause major investments to assure field production. Not only the costs for the H2S treatment materials (e.g. biocides, nitrate) but also the investments in corrosion inhibitors, H2S resistant pipes, valves, filters, and the upgrade of the processing facilities have a large financial impact. Furthermore HSE related measures and required safety and monitoring systems are increasing substantially the operation costs.
In view of KOC's ambitions to increase the oil production by 20% by 2020 and the subsequently expected increase of H2S production, a contry-wide coordination of the treatment concepts for the H2S could improve the efficiency of the mitigation operations and could potentially reduce the investments and operation costs related to the sour gas issue.
The M prospect is located in the B block flanking the northern boundary of the Doba basin in Chad, Africa. D-1, M-1 and M-2 wells were drilled by OPIC Africa Corporation in 2015 and 2016 respectively. After DST testing, M-1 and M-2 wells successfully discovered oil with good production rate. To further understand the spatial thickness distribution of the tested reservoir sand in order to estimate the in place oil reserve associated with the discovery wells, interbedded thin sand interpretation technique was built through spectrum decomposition modeling and analysis. Four stratigraphic 2D channel filled sand models were built by integrating the P-velocity and the density logs of two discovery wells. Sand thickness interpretation pitfall associated with wedge model was recognized based on the study result. Based on the modeling results, we concluded that dim amplitude response may also be interpreted as interbedded thin sands rather than zero thickness sand. This new sand thickness interpretation technique was applied to the sand thickness interpretation of spectrum decomposed 3D seismic amplitude volumes. The sand interpretation results based on spectrum decomposition modeling is consistent with the drilling results.
Presentation Date: Monday, September 25, 2017
Start Time: 2:15 PM
Location: Exhibit Hall C/D
Presentation Type: POSTER
Nestyagin, Andrey (ADCO) | Al Arfi, Saif (ADCO) | Mostafa, Hassan (Weatherford) | Elkholy, Mohamed (Weatherford) | Fekry, Mohamed (Weatherford) | Awad, Huda (Weatherford) | Mohamed, Omar (Weatherford)
Proper Well Placement in multi layers thin carbonate reservoir could be challenging due to high geological uncertainty. Using radioactive sources to evaluate porosity & formation dipping is effective, but considering the drilling environment & high risk to get stuck makes a lot of restrictions on using of the nuclear tools. This paper is a case study illustrating utilizing absolutely sourceless azimuthal sonic in a comparison with conventional radioactive density as a highly effective alternative sourceless geosteering method & adds extra formation evaluation values. The technique provides azimuthal sonic data were acquired with a focused unipole tool which recorded the measured waveforms and computed Compressional and Shear velocities in 16 azimuthal bins yet Quadrant Compressional and Shear slowness were computed by stacking all 16 bins of data in Realtime, which gave very high signal-to-noise ratios and excellent data quality. The azimuthal Quadrant real-time sonic porosities were effectively used to well placement in the target reservoir, later on the full 16 bin azimuthal memory were examined to understand the additional advantages of using the azimuthal sonic even before approaching the main bed boundaries. Both of Azimuthal Density & Azimuthal Sourceless Sonic measurements were able to detect the boundaries of the target zone, allowing accurate stratigraphic interpretation as well as dip picking calculation to ensure proactive geosteering and maintain the well trajectory as per the plan. It was proven that the Sonic lengthy depth of detection can add an additional safety margin to enable adjusting the well trajectory in the reservoir at the optimal angle, the comparison chanced later against the Azimuthal density image was matching very well and emphasised the formation dipping. This case study proves the capability of using LWD Azimuthal sonic as an effective & alternative sourceless porosity for geosteering and formation dipping calculation purposes.