3D Geomechanics Modeling and Shale Anisotropy for Wellbore Stability and Horizontal Well Optimization, Middle Nazym Field, Western Siberia, Russia

Author(s):  
E. Konstantinovskaya ◽  
O. Grachev ◽  
Yu. Petrakov ◽  
A. Sobolev ◽  
I. Mikhaltseva ◽  
...  
2020 ◽  
pp. 54-62
Author(s):  
A. B. Tulubaev ◽  
E. V. Panikarovskii

In the article, we analyze types of drilling mud, which are used to drilling intervals of permafrost rocks; the importance of wellbore stability is noted. Wedescribethemain technologies, which have been being applied in the north of Western Siberia; these technologies are aimed at minimizing the loss wellbore stability due to violation of the temperature conditions in the well. We also analyze hydrocarbon systems, taking into account foreign experience, which is based on prospecting and exploratory drilling of ice deposits in Greenland and Antarctica. The article draws your attention to using synthetic fluids, monoesters and chladones. The difficulties of the existing technology and the disadvantages of the hydrocarbon systems are highlighted. We propose to apply a new cryogenic drilling technology, which consists in the use of synthetic fluorine-containing agents as flushing fluid at low temperatures. The text gives valuable information on composition of the proposed flushing fluid and the prospects of using the technology to prevent complications. Much attention is given to issue of manufacturing the main chemical reagent with the reduction of the generalized production chain of its production from the starting material, it is fluorspar.


2021 ◽  
Author(s):  
Rida Mohamed Elgaddafi ◽  
Victor Soriano ◽  
Ramadan Ahmed ◽  
Samuel Osisanya

Abstract Horizontal well technology is one of the major improvements in reservoir stimulation. Planning and execution are the key elements to drill horizontal wells successfully, especially through depleted formations. As the reservoir has been producing for a long time, pore pressure declines, resulting in weakening hydrocarbon-bearing rocks. Drilling issues such as wellbore stability, loss circulation, differential sticking, formation damage remarkably influenced by the pore pressure decline, increasing the risk of losing part or even all the horizontal interval. This paper presents an extensive review of the potential issues and solutions associated with drilling horizontal wells in depleted reservoirs. After giving an overview of the depleted reservoir characteristics, the paper systematically addresses the major challenges that influence drilling operations in depleted reservoirs and suggests solutions to avoid uncontrolled risks. Then, the paper evaluates several real infill drilling operations through depleted reservoirs, which were drilled in different oilfields. The economic aspect associated with potential risks for drilling a horizontal well in depleted reservoirs is also discussed. The most updated research and development findings for infill drilling are summarized in the article. It is recommended to use wellbore strengthening techniques while drilling a horizontal well through highly depleted formations. This will allow using higher mud weight to control unstable shales while drilling through the production zone. Managed Pressure Drilling should be considered as the last option for highly depleted formations because it will require a greater level of investment which is not going to have a superior rate of return due to the lack of high deliverability of the reservoir. Using rotary steerable systems is favored to reduce risks related to drilling through depleted formations. Precise analysis of different drilling programs allows the drilling team to introduce new technology to reduce cost, improve drilling efficiency and maximize profit. It is the responsibility of the drilling engineer to evaluate different scenarios with all the precautions needed during the planning stage to avoid unexpected issues. The present market conditions and the advancement in technologies for drilling horizontal wells increase the feasibility of producing the depleted reservoirs economically. This paper highlights the challenges in drilling horizontal wells in highly depleted reservoirs and provides means for successfully drilling those wells to reduce risks while drilling


2012 ◽  
Author(s):  
Andrey Platunov ◽  
Maxim Nikolaev ◽  
Fedor Leskin ◽  
Zdenko Kaluder ◽  
Yuri Masalkin ◽  
...  

2012 ◽  
Author(s):  
Andrey Platunov ◽  
Maxim Nikolaev ◽  
Fedor Leskin ◽  
Zdenko Kaluder ◽  
Yuri Masalkin ◽  
...  

2021 ◽  
Author(s):  
Sukru Merey ◽  
Can Polat ◽  
Tuna Eren

Abstract Currently, many horizontal wells are being drilled in Dadas shales of Turkey. Dadas shales have both oil (mostly) and gas potentials. Thus, hydraulic fracturing operations are being held to mobilize hydrocarbons. Up to 1000 m length horizontal wells are drilled for this purpose. However, there is not any study analyzing wellbore stability and reservoir geomechanics in the conditions of Dadas shales. In this study, the directions of horizontal wells, wellbore stability and reservoir geomechanics of Dadas shales were designed by using well log data. In this study, the python code developed by using Kirsch equations was developed. With this python code, it is possible to estimate unconfined compressive strength in along wellbore at different deviations. By analyzing caliper log, density and porosity logs of Dadas shales, vertical stress of Dadas shales was estimated and stress polygon for these shale was prepared in this study. Then, optimum direction of horizontal well was suggested to avoid any wellbore stability problems. According to the results of this study, high stresses are seen in horizontal directions. In this study, it was found that the maximum horizontal stress in almost the direction of North-South. The results of this study revealed that direction of maximum horizontal stress and horizontal well direction fluid affect the wellbore stability significantly. Thus, in this study, better horizontal well design was made for Dadas shales. Currently, Dadas shales are popular in Turkey because of its oil and gas potential so horizontal drilling and hydraulic fracturing operations are being held. However, in literature, there is no study about horizontal wellbore designs for Dadas shales. This study will be novel and provide information about the horizontal drilling design of Dadas shales.


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