Even though coring of rocks is the best way to characterize reservoir and source rocks geologically and petrophysically, this method is considered expensive, having a relatively high cost per foot. Alternatively, side-wall cores and cuttings are widely used in reservoir characterization at a relatively low cost. However, this method has limitations related to cuttings bad physical conditions, size, mixed lithological and mineralogical characteristics which make the commonly used conventional evaluation methods not applicable. This study introduces a robust combination of digital and conventional core analysis methods to overcome these limitations and characterize reservoir and shale cuttings derived from two hydrocarbon-bearing formations in New Zealand.
Initially, all cuttings from both formations were screened based on their cutting sizes and later based on the visually observed textures using the stereomicroscope. This helped in selecting representative cuttings for the main identified textures. These cuttings were CT imaged at a resolution ranging from 40 to 4 microns/voxel resolution in order to confirm their rock textures and sedimentary structures for better characterization results. Next, mercury injection capillary pressure (MICP), X-ray diffraction (XRD), and petrographical analysis were conducted on all selected cuttings with different rock textures in order to understand the pore types, textural variations, diagenetic overprints and mineralogy of the cuttings samples. Then, they were scanned at optimum resolutions using Micro CT and 3D FIB-SEM microscopies. Finally, all acquired images were segmented digitally and 3D rock volumes were created. These volumes were used in computing porosity, permeability, formation factor resistivity (FRF) and poroperm trends digitally using numerical simulation techniques.
Conventional and digital rock analysis showed that the cuttings derived from the reservoir interval are composed of an argillaceous sandstone with a very good computed porosity (18% up to 31%) and permeability (30 to 200 mD). On the other hand, the cuttings derived from the shale source rock interval, which were predominately composed of clay minerals, have a computed porosity of 12% to 13% (mainly inorganic pores) and an absolute permeability in the range of 0.5 to 4 Micro-Darcy. The digital poroperm trend analysis identified distinct poroperm trends for each formation which helped in understanding their petrophysical aspects.
This integration between conventional and digital methods provided better geological and petrophysical understanding of both formations using a limited number of cuttings, less cost and time.
Al-Azmi, Mejbel Saad (Kuwait Oil Company) | Al-Otaibi, Fahad (Kuwait Oil Company) | Kumar, Joshi Girija (Kuwait Oil Company) | Tiwary, Devendra (Kuwait Oil Company) | Al-Ashwak, Samar (Kuwait Oil Company) | Dzhaykiev, Bekdaulet (Baker Hughes, a GE Company) | Shinde, Neha (Baker Hughes, a GE Company) | Hardman, Douglas (Baker Hughes, a GE Company) | Noueihed, Rabih (Baker Hughes, a GE Company) | Gadkari, Shreerang (Baker Hughes, a GE Company)
The complex nature of the reservoir dictated comprehensive formation evaluation logging that was typically done on wireline. The high angle designed for maximum reservoir exposure, high temperature, high pressure (HTHP), differential reservoir pressure and wellbore stability challenges necessitated a new approach to overall formation evaluation. The paper outlines Formation Evaluation strategy that reduced risk, increased efficiency and saved money, while ensuring high quality data collection, integration and interpretation.
After review of all risks, a decision to utilize Managed Pressure Drilling (MPD) for wellbore stability, Logging While Drilling (LWD) to replace wireline and Advanced Mudlogging Services was implemented. The Formation Evaluation team utilized LWD resistivity, neutron, density and nuclear magnetic resonance logs supplemented with x-ray diffraction (XRD), x-ray fluorescence (XRF) and advanced mud gas analysis to ensure comprehensive analysis. The paper outlines workflows and procedures necessary to ensure all data from LWD, XRF, XRD and mud gas are integrated properly for the analysis.
Effects of Managed Pressure Drilling on mud gas interpretation as well as cuttings and mud gas depth matching are addressed. Depth matching of all data, mud gasses, cuttings and logs are critical for detailed and accurate analysis and techniques are discussed that ensure consistent results. Complex mineralogy due to digenesis and effect of LWD logs are evident and only reconciled by detailed XRF and XRD data. The effects of some conductive mineralogy are so dramatic as to infer tool function compromise. The ability to determine acceptable tool response from tool failures eliminates unnecessary trips and leads to efficient operations. The final result of the above data collection, QC and processing resulted in a comprehensive formation evaluation interpretation of high confidence.
Finally, conclusions and recommendations are summarized to provide guidelines in Formation Evaluation in similar challenging highly deviated, HTHP, complex reservoir environments on land and offshore.
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.
This paper discusses the first multilateral well with a Level-4 junction combined with an inflow-control device (ICD) planned, designed, and drilled in the Upper Burgan reservoir of Raudhatain field, north Kuwait. Several designs for autonomous inflow-control devices (AICDs) are available. The comparative properties and abilities of these designs are the focus of this paper. As part of a project that involves the use of four artificial islands to drill and complete more than 300 extended-reach-drilling (ERD) wells in a giant offshore oil field, several completion designs have been piloted for brownfield development.
Multilateral wells with smart completions controlled by different flow-control technologies offer great operational flexibility, with each lateral able to be operated and optimized independently. The use of intelligent software is on the rise in the industry and it is changing how engineers approach problems. A series of articles explores the potential benefits and limitations of this emerging area of data science. This paper discusses the first multilateral well with a Level-4 junction combined with an inflow-control device (ICD) planned, designed, and drilled in the Upper Burgan reservoir of Raudhatain field, north Kuwait.
The operator piloted a new well-completion design combining inflow-control valves (ICVs) in the shallow reservoir and inflow-control devices (ICDs) in the deeper reservoir, both deployed in a water-injector well for the first time in the company’s experience. This paper discusses the first deployment of an ICD system combined with an OBC system for a workover operation in a mature producer well in the Kingdom of Saudi Arabia. With the objective of increasing its production to 4.0 million BOPD, the Kuwait Oil Company (KOC) is developing its fields with optimum technology solutions. This paper discusses the first multilateral well with a Level-4 junction combined with an inflow-control device (ICD) planned, designed, and drilled in the Upper Burgan reservoir of Raudhatain field, north Kuwait. Work conducted in the Surmont field of Alberta, Canada, provided an excellent starting point to optimize flow-control improvements to the SAGD process.
Green fields today mostly can be regarded as marginal fields and successfully developed. It covers the complete assessment of the oil and gas recovery potential from reservoir structure and formation evaluation, oil and gas reserve mapping, their uncertainties and risks management, feasible reservoir fluid depletion approaches, and to the construction of integrated production systems for cost effective development of the green fields. Depth conversion of time interpretations is a basic skill set for interpreters. There is no single methodology that is optimal for all cases. Next, appropriate depth methods will be presented. Depth imaging should be considered an integral component of interpretation. If the results derived from depth imaging are intended to mitigate risk, the interpreter must actively guide the process.
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.
Moving their directional drillers into their Houston real-time remote operations centers has improved drilling efficiency for two of the top shale producers. This paper presents a factory-model approach to improving CT drillout performance that has been used successfully for more than 3 years and has become standard practice. The oil industry is currently undergoing a technological transformation that will add value, improve processes, and reduce cost. Future drilling engineers will have knowledge of robotics, automation, and organizational efficiency, which is highly appealing for recruitment. This paper describes challenges faced in a company’s first deepwater asset in Malaysia and the methods used to overcome these issues in the planning stage.