Integrated Geomechanical Operations for Successful Field Development: A Case Study from Western Offshore, India

2021 ◽  
Author(s):  
Pawandeep Bagga ◽  
Tapan Kidambi ◽  
Ashish Sharma ◽  
Anjana Panchakarla ◽  
Aditee Kulkarni

Abstract This paper deals with the field development study for an offshore field in the western part of India. The main points of focus are holistic execution of integrated workflows for the delivery of subsea oil and gas wells from a jack up platform in this region. Given that the encountered formations encountered in wells posed significant challenges during the drilling phase, a field level geomechanics study was commissioned to understand and mitigate any challenges and effect smooth drilling and logging operations. Understanding the geomechanical effects by analysing the offset wells drilled in the region provided significant insights into the potential challenges faced while exploring target formations. The proposed well locations were drilled in a structurally complex geological setting. From the analysis of previously drilled wells in the region, it was evident that the variation in insitu properties of the lithologies and the extreme heterogeneity and vugular nature of the encountered carbonates caused significant drillability issues with subsequent losses, excessive cuttings, and several back reaming cycles impacting rig time and leading to generally poor borehole conditions. On the other hand, the shales encountered at shallower depths presented a different challenge, especially with a high swelling tendency, adding to progressively worsening hole conditions and significant fluid invasion. Finally, the basal clastics and the depleted zones with variable rock strengths added to the borehole instability issues, with particular zones projecting losses while others showed influxes. In light of such a plethora of issues, an integrated approach including dynamic real time monitoring of operations, structured LWD and wireline logging programmes, a high level petrophysics, formation evaluation and borehole acoustics for shear radial profiling was carried out. A fit for purpose geomechanical model was built encompassing the results of these analyses and was continually updated in real time during the operations phase. Given the variability in the pressures, temperatures and operational mud weights in each section, execution for successful delivery of the wells was further aided by identification of the optimal mud systems, critical casing setting depths and real time drilling optimization, ensuring good borehole quality throughout for further logging and testing programmes.

2021 ◽  
Author(s):  
Joseph Rizzo Cascio ◽  
Antonio Da Silva ◽  
Martino Ghetti ◽  
Martino Corti ◽  
Marco Montini

Abstract Objectives/Scope The benefits of real-time estimation of the cool down time of Subsea Production System (SPS) to prevent formation of hydrates are shown on a real oil and gas facility. The innovative tool developed is based on an integrated approach, which embeds a proxy model of SPS and hydrate curves, exploiting real-time field data from the Eni Digital Oil Field (eDOF, an OSIsoft PI based application developed and managed by Eni) to continuously estimate the cool down time before hydrates are formed during the shutdown. Methods, Procedures, Process The Asset value optimization and the Asset integrity of hydrocarbon production systems are complex and multi-disciplinary tasks in the oil and gas industry, due to the high number of variables and their synergy. An accurate physical model of SPS is built and, then, used to develop a proxy model, which integrates hydrate curves at different MeOH concentration, being able to estimate in real time the cool down time of SPS during the shutdown exploiting data from subsea transmitters made available by eDOF in order to prevent formation of hydrates. The tool is also integrated with a user-friendly interface, making all relevant information readily available to the operators on field. Results, Observations, Conclusions The integrated approach provides a continues estimation of cool down time based on real time field data (eDOF) in order to prevent formation of hydrates and activate preservation actions. An accurate physical model of SPS is built on a real business case using Olga software and cool down curves simulated considering different operating shutdown scenarios. Hydrate curves of the considered production fluid are also simulated at different MeOH concentration using PVTsim NOVA software. Off-line simulated curves are then implemented as numerical tables combined with eDOF data by an Eni developed fast executing proxy model to produce estimated cool down time before hydrates are formed. A graphic representation of SPS behavior and its cool down time estimation during shutdown are displayed and ready to use by the operators on field in support of the operations, saving cost and time. Novel/Additive Information The benefits of real time estimation of the cool down time of SPS to prevent hydrates formation are shown in terms of saving of time and cost during the shutdown operations on a real case application. This integrated approach allows to rely on a continue, automatic and acceptably accurate estimate of the available time before hydrates are formed in SPS, including the possibility to be further developed for cases where subsea transmitters are not available or extended to other flow assurance issues.


Author(s):  
Rui Pedro Marques ◽  
Henrique Santos ◽  
Carlos Santos

This article presents a comparator module which aims to compare, in real time, executions of organizational transactions with patterns of behaviors of these transaction executions, allowing the determination of which execution pattern is being followed by running each transaction. This is according to information received by the internal control mechanisms, which continuously monitors the transaction executions. A possible application using this module was deployed and results were obtained from a case study. The results prove effectiveness of the module, mainly because it is able to assess business compliance and the qualitative risk associated to each transaction execution while it is running, enabling an efficient continuous auditing application. The innovation of this article is ensured by the use of an ontological model to represent organizational transactions, which can be applicable to any type of transaction in any business area in order to audit transactions at a very low level, contrary to what happens in traditional auditing, which occurs at a high level (e.g. compare whether a completed transaction has followed a set of procedures). Besides the conceptualization, this work presents some technical details of development and discussion of results from the case study.


2021 ◽  
Author(s):  
Kumar Nathan ◽  
M Arif Iskandar Ghazali ◽  
M Zahin Abdul Razak ◽  
Ismanto Marsidi ◽  
Jamari M Shah

Abstract Abandonment is considered to be the last stage in the oil gas field cycle. Oil and gas industries around the world are bounded by the necessity of creating an abandonment program which is technically sound, complied to the stringent HSE requirement and to be cost-effective. Abandonment strategies were always planned as early as during the field development plan. When there are no remaining opportunities left or no commercially viable hydrocarbon is present, the field need to be abandoned to save operating and maintenance cost. The cost associated on abandonment can often be paid to the host government periodically and can be cost recoverable once the field is ready to be abandoned. In Malaysia, some of the oil producing fields are now in the late life of production thus abandonment strategies are being studied comprehensively. The interest of this paper is to share the case study of one of a field that is in its late life of production and has wells and facilities that planned to be abandon soon. The abandonment in this field is challenging because it involves two countries, as this field is in the hydrocarbon structure that straddling two countries. Series of techno-commercial discussion were held between operators of these two countries to gain an integrated understanding of the opportunity, defining a successful outcome of the opportunity and creating an aligned plan to achieve successful abandonment campaign. Thus, this paper will discuss on technical aspects of creating a caprock model, the execution strategies of abandoning the wells and facilities and economic analysis to study whether a joint campaign between the operators from two countries yields significantly lower costs or otherwise.


2020 ◽  
Author(s):  
Hiren Kasekar ◽  
Usama Ghauri ◽  
Michael Nevin ◽  
Raphaele Mel ◽  
Mattheus Uijttenhout ◽  
...  

Processes ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 1682
Author(s):  
Antioco López-Molina ◽  
Debalina Sengupta ◽  
Claire Shi ◽  
Eman Aldamigh ◽  
Maha Alandejani ◽  
...  

Biorefineries provide economic, environmental, and social benefits towards sustainable development. Because of the relatively small size of typical biorefineries compared to oil and gas processes, it is necessary to evaluate the options of decentralized (or distributed) plants that are constructed near the biomass resources and product markets versus centralized (or consolidated) facilities that collect biomass from different regions and distribute the products to the markets, benefiting from the economy of scale but suffering from the additional transportation costs. The problem is further compounded when, in addition to the economic factors, environmental and safety aspects are considered. This work presents an integrated approach to the design of biorefining facilities while considering the centralized and decentralized options and the economic, environmental, and safety objectives. A superstructure representation is constructed to embed the various options of interest. A mathematical programming formulation is developed to transform the problem into an optimization problem. A new correlation is developed to estimate the capital cost of biorefineries and to facilitate the inclusion of the economic functions in the optimization program without committing to the type of technology or the size of the plant. A new metric called Total Process Risk is also introduced to evaluate the relative risk of the process. Life cycle analysis is applied to evaluate environmental emissions. The environmental and safety objectives are used to establish tradeoffs with the economic objectives. A case study is solved to illustrate the value and applicability of the proposed approach.


2021 ◽  
Vol 40 (5) ◽  
pp. 357-364
Author(s):  
Jaewoo Park ◽  
Craig Hyslop ◽  
Da Zhou ◽  
Arjun Srinivasan ◽  
Patricia Montoya ◽  
...  

Carbonate reservoirs are increasingly becoming an important resource for hydrocarbon production because they contain the majority of remaining proven oil and gas reserves. In this context, carbonate reservoirs could represent new opportunities; however, there is still a lack of understanding of their subsurface status and characterization. Carbonate reservoirs are more difficult to evaluate than their siliciclastic counterparts because many aspects of carbonate rocks make their seismic image signature complex and difficult to interpret. Moreover, the presence of complex overburden such as shallow gas accumulation can exacerbate amplitude and phase fidelity at the reservoir, which introduces an additional imaging challenge. This makes field development of carbonate reservoirs extremely difficult because field development requires detailed delineation of characteristic karst features to avoid drilling hazards and sudden water breakthrough. In this paper, we demonstrate that a tight integration of signal processing, depth model building, and imaging, as well as near-real-time seismic interpretation feedback, is the key to success for imaging complex carbonate reservoirs with overburden challenges. Our findings show that such an integrated approach can result in a substantially better image, reduced depth uncertainty, and better delineation of karst and fractures. It can also aid in well placement and improve reservoir property modeling.


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