The basic objective of this course is to introduce the overview and concept of production optimisation, using nodal analysis as a tool in production optimisation and enhancement. The participants are exposed to the analysis of various elements that help in production system starting from reservoir to surface processing facilities and their effect on the performance of the total production system. 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.
This course is designed for petro physics and reservoir engineers who are involved in formation sampling and testing. To learn about reservoir characterisation using formation testers, to be able to interpret pressure and fluid properties, and to design a successful sampling and testing operation. This class is designed for geophysicists, reservoir engineers and any engineers involved or interested in wireline formation sampling and testing including petro physical engineers, production engineers and testing engineers. There are no special requirements for this course. It is recommended for participants to bring their own examples to contribute to course discussions.
This year, as part of the Opening Ceremony, SPE brings you two panel sessions that will focus on the conference theme “Co-operating Towards a More Competitive Environment to Encourage Investment Projects.” The panels will represent two different perspectives—the investors and operators in the region. Digitalisation is emerging as a technological driver of change around the world and is transforming how companies in the oil and gas industry operate. A wave of digital technologies and initiatives are leading this new era of innovation and opportunity. Investments in programmes such as analytics, data science, artificial intelligence, cloud computing, and other emerging technologies are being pursued to improve safety, reliability, and efficiency with the expectation of delivering significant value through improved processes and systems.
Africa (Sub-Sahara) ExxonMobil will drill its first exploratory well offshore Liberia this month, the company announced on 18 October. A deepwater well is planned on the Liberia-13 Block, which is about 50 miles off the coast of the West African country. Solo Oil plans to spud the Ntorya-2 appraisal well in Tanzania next month. The drilling pad is a mile southwest of the 2012 Ntorya-1 discovery well, which was tested at rates of 20.1 MMcf/D of gas and 139 B/D of condensate. An independent report estimated the discovery to hold 153 Bcf of gas in place, of which 70 Bcf is considered a gross best-estimate contingent resource. A gross best estimate of more than 1 Tcf of gas in place has been made for the Ntorya prospect as a whole, in which the company has a 25% interest. Asia Pacific BP has decided to abandon drilling plans in the Great Australian Bight offshore southern Australia, an area in which prospective drilling has long been contested by environmentalists.
Differential compaction is an inherent process in carbonate systems that is thought to produce early natural fractures prior to any significant burial. Such fractures can persist and can be major permeability pathways, including areas of minor tectonic overprint. We forward model differential compaction fracturing in a carbonate reservoir in effort to predict the location of fractures in the subsurface.
3D finite-element geomechanical models are created to simulate differential compaction fracturing at a carbonate platform scale (kilometers) and the smaller carbonate build-up scale (10s of meters) commonly present within carbonate platforms. Interpreted seismic surfaces of key reservoir horizons are used as an input for the platform-scale model. Geometry of carbonate build-up from an outcrop analog is used for the build-up scale models. In both type of models layers identified to be compaction prone are restored to their expected pre-compaction state. A simplified mechanical stratigraphy scheme is adopted to distribute mechanical properties within the models consistent with their expected pre-burial properties.
Geomechanical modeling in this study was applied to a field which includes two carbonate platforms at different stratigraphic levels. Modeling results predict increased fracture intensity at the windward margin of the carbonate platform. This coincides with increased windward-leeward asymmetry of an underlying older platform. Increased fracture intensity is predicted at the center of the platform where the underlying older platform displays significantly less asymmetry. Predicted fracture locations over the platform top also correspond with the location of carbonate build-ups identified from seismic data. Fracture observations from image logs and indirectly from mud loss data within the upper platform are consistent with our modeling results. Predicted areas of greatest fracture intensity correspond with the location of wells with the highest fracture intensity observed from image logs.
Build-up scale models suggest that the build-up shape exerts a major control on the resulting differential compaction fracture pattern. Elongate build-ups tend to produce fractures oriented parallel to their axes. Circular build-ups tends to produce radial fracture patterns. Fracture orientation from image logs along with build-up shape observed using the coherence seismic attribute are consistent with these findings.
This study offers a process-based fracture modeling approach that can enhance the predictability of the location and orientations of natural fractures in carbonate reservoirs.
Epoxy-resin applications in oil and gas wells have significantly increased for remediation and sustained-casing-pressure mitigation because of its solids-free nature and excellent thermomechanical/bonding properties when used either as a single component or as a resin/cement-enhanced composite. Therefore, it is imperative to assess the formation and degradation of structures in cured epoxy resin at downhole temperatures, particularly because hydrocarbon production requires long-term wellbore integrity.
Differential scanning calorimetry (DSC) was used to determine the glass transition temperature (Tg) of the proposed resin system, and thermogravimetric analysis (TGA) was used to characterize the thermal degradation response by monitoring the resin specimens’ mass loss over time under controlled temperatures ranging from 300 to 680°F at atmospheric pressure. The thermal kinetic response based on TGA was then modeled using the Arrhenius equation to predict the resin lifetime under expected wellbore conditions. A uniaxial load frame Tinius Olsen tester was used to assess the mechanical response of the resin system under elevated temperatures.
For a resin system subjected to downhole temperatures of 263°F, the model predicts that reaching 10% mass loss by thermal degradation can take more than 160 years, which is beyond the operational life of the wells where the system is evaluated. This indicates that the investigated resin system provides long-term dependability that ultimately results in reduction of intervention/remediation costs, along with production maximization. Additionally, the resin mechanical properties were evaluated at different temperatures to assess their response to expected thermal loading, which resulted in competent barriers that can withstand the cyclic loads generated by continuous wellbore operations. This work also presents a case study in which an epoxy-resin-cement composite is used as an annular barricade to help prevent and reduce sustained casing pressure. The resin-cement composite was placed in the annular section as a chemical packer tailored to improve bonding to steel pipe, along with optimizing its mechanical response to cyclic downhole loads, which resulted in no up-to-date sustained casing pressure. Furthermore, Cement Bond Log (CBL) results further support the optimum annular integrity attained when utilizing a cement-resin composite as chemical packer for enhanced isolation and annular pressure buildup mitigation.
The present paper describes the results of analysis of depositional environment and tectonic setting within Karaton-Tengiz uplift zone in the southeastern part of the Pre-Caspian basin. The main purpose of the study is generalization and interpretation of geological and geophysical data for creation of stratigraphic charts and a description of lithological and tectonic processes for reconstruction of the structural history of pre-salt prospective traps located close to Tengiz field.
It is known that carbonates are "born, not made"; hence, their characteristics can give an insight into their depositional environment. The combination of such factors as availability of the light, warm climate, chemical composition and transparency of the water define the growth of the reef-building organisms. The highest carbonate production takes place close to the water surface; therefore, facies and texture of carbonates may be linked to the sea level changes. This means that understanding of the depositional environment and sequence stratigraphy may be used for a potential reservoir description where no well data is available. As a general understanding of the relative sea level fluctuations and its effect on carbonate growth, comparison of vertical thickness of studied platforms was carried out.
Analysis of regional seismic reflectors P3 (Top of Middle Devonian, tentative), P2D (Top of Upper Devonian), P2 (Top of Carboniferous), P1 (Top of Permian), VI (Kungurian salt deposits), V (surface of unconformity, Triassic), III (Top of Jurassic), II (Top of Lower Cretaceous) was also carried out for understanding of tectonic processes. Dipping of reflectors, thickness and depth variation of time-equivalent units, unconformities may indicate the change in tectonic setting. The shallowest depth of top of carbonates is observed on Tazhigali-Pustynnaya structure, gradually deepening towards Ansagan and Maksat to the south-southeast. Also, post-salt III and V reflective horizons are inclined from the north to the south of Karaton-Tengiz uplift zone.
Tectonic deepening in the south-southeast direction took place in several stages. The first stage, most probably, took place in Late Devonian–Early Carboniferous, as the result of which Ansagan and Maksat structures drowned. In the northern part of the Karaton-Tengiz uplift, the growth of reefs continued up to Late Carboniferous.
Well logging interpretation and published papers were integrated when possible. As the result, a conceptual model of the geological history and stratigraphic charts were created for the studied region.
Kazakhstan has a world class endowment of petroleum resources including some of the world’s most fascinating and challenging super giants. With a large base of mature assets and the development of the Kashagan field, it is a good time to look for resources that will drive and sustain production levels for future generations. The oil and gas industry has a history of building reserves through frontier exploration, near-field exploration, and building reserves in existing reservoirs, through better definition of the reservoir and application of advanced technologies. All of these opportunities are present in the Republic of Kazakhstan: there is the enigmatic deep carbonate resource which is the focus of the ambitious Eurasia project; the further definition and development of Kazakhstan’s supergiants which can make large additions to their proven reserves; opportunities for nearfield exploration building upon existing infrastructure; and a large base of older producing fields which can be sustained through improved/enhanced oil recovery and new business approaches. The effort to add reserves in all of these areas is key to bringing on future production over the short, medium and long term.
Each edition of the Olympic Games brings together remarkable athletes, volunteers, and spectators of all nationalities in a long-anticipated competition. While Brazil just finished hosting its first summer Olympics in the coastal city of Rio de Janeiro, in the world of oil and gas megaprojects another type of competition is in play--that of market share. More akin to a marathon race than a sprint, Olympic-sized oil and gas megaprojects take years to come to fruition and require billions of dollars in development costs. Not every planned megaproject will make it to the finish line. What does it take for these ultraambitious projects to succeed?
Li, Guanghuan (Drilling Fluids Technology Service Company, CNPC Bohai Drilling Engineering Co. Ltd.) | Ma, Hong (Drilling Fluids Technology Service Company, CNPC Bohai Drilling Engineering Co. Ltd.) | Long, Tao (Drilling Fluids Technology Service Company, CNPC Bohai Drilling Engineering Co. Ltd.) | Huang, Daquan (Drilling Fluids Technology Service Company, CNPC Bohai Drilling Engineering Co. Ltd.) | Tian, Zengyan (Drilling Fluids Technology Service Company, CNPC Bohai Drilling Engineering Co. Ltd.) | Zhang, Aishun (Drilling Fluids Technology Service Company, CNPC Bohai Drilling Engineering Co. Ltd.) | Wang, Weizhong (Drilling Fluids Technology Service Company, CNPC Bohai Drilling Engineering Co. Ltd.) | Hou, Shili (Drilling Fluids Technology Service Company, CNPC Bohai Drilling Engineering Co. Ltd.) | Gong, Chunwu (Drilling Fluids Technology Service Company, CNPC Bohai Drilling Engineering Co. Ltd.)
Oily cuttings are hazardous wastes containing oil, hydrocarbons and heavy metals, which generate a significant risk to human and enviroment without appropriate treatment. The common treatment, including heating, burning, microbiological degradation and so on, are not fast and effective enough to solve the pollution problem caused by oily cuttings. This article provides a method with higher efficiency and lower cost. An intelligent cleaning agent, synthesized for cleaning oily cuttings, is easy to dissolve in water and makes oil and water easily emulsify during cleaning process, so as to achieve the purpose of removing oil. By adjusting the pH, the emulsion will be automatically demulsified after statis, and then the oil and water are separated from each other, which simplify the progress of treatment. Ultrasonic technology is assisted to clean the oily cuttings, which effectively reduces the amount of cleaning agent and increases the treating efficiency of the cleaning agent. In this paper, the effects of the cleaning agent dosage, heating temperature and ultrasonic time on the deoiling ratio are analyzed. The oil recovery rate is above 90% with the dosage of 7.5g/L oil cleaning agent under the 55 °C and 10 minutes. The recovered oil has good quality and meets the demand for preparation of oil-based drilling fluid. The residual wastewater, including the cleaning agent, can be reused as cleaning liquid by adjusting the pH to neutral and adding fresh cleaning agent. This technique improves the treating efficiency of oily cutting and greatly lower the cost, which would have a high value to popularize.