scholarly journals Electromagnetic propagation logging while drilling data acquisition method based on undersampling technology

2021 ◽  
Vol 18 (5) ◽  
pp. 653-663
Author(s):  
Xinghan Li ◽  
Wenxiu Zhang ◽  
Wenxuan Chen ◽  
Yali Zhang ◽  
Jian Zheng ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Correction Coefficient ◽  
Sampled Data ◽  
Electromagnetic Propagation ◽  
Oil And Gas Exploration ◽  
Unconventional Oil And Gas ◽  
Logging While Drilling ◽  
Analogue To Digital ◽  
Acquisition Method ◽  
Selection Of

Abstract With the development of complex and unconventional reservoirs, oil and gas exploration becomes increasingly difficult. Highly deviated wells/horizontal wells are widely used. The electromagnetic propagation logging while drilling (LWD) is more effective in complex geological environment detection owing to geological orientation and real-time formation evaluation. However, its operating frequency is generally at the MHz level. Traditional acquisition techniques require an analogue to digital converter with high sampling rates, which will introduce complex circuit structures and increase sampling costs. The undersampling technology has overcome these disadvantages. The difficulties in the undersampling technology include the selection of an undersampling frequency and the acquisition of a signal correction coefficient. The range of undersampling frequencies and a correction coefficient has been developed to process the electromagnetic propagation LWD measurements in this paper. The range of undersampling frequency ensures the validity of the sampled data. The correction coefficient ensures that different frequency signals use the same undersampling frequency to obtain the same frequency recovery signal. The correctness of these parameters is verified by simulation and field data examples. The range of undersampling frequency and a correction coefficient has been applied, improving the data stability and providing reliable technical support for the exploration and development of unconventional oil and gas.

A Mechanical Analysis of BHA Used in Casing-Window-Milling for Sidetracking

2014 ◽  
Vol 933 ◽  
pp. 265-271
Author(s):  
Zhao Hui Xu ◽  
De Li Gao
Keyword(s):  
Oil And Gas ◽  
Mechanical Analysis ◽  
Drill String ◽  
Drilling Parameters ◽  
Unconventional Oil And Gas ◽  
Research Achievement ◽  
Stress And Deformation ◽  
Analysis Models ◽  
The Relationship ◽  
Selection Of

As more and more sidetracking old wells are required in mature fields, a lot of applications in casing window milling technology, such as drilling for unconventional oil and gas, multi-lateral wells and laterals, are applied. In this paper, the mechanical properties of the BHA in different stages of window milling for sidetracking are analyzed in detail. Based on the commonly-used vertical and horizontal bending analysis, mechanical analysis models of BHA with three bits for windows milling are proposed. With these mechanical analysis models, different mechanical parameters of window milling BHA at different stages during the window operation can easily be calculated. The research achievement in this paper is helpful not only to understand the relationship between drilling parameters and drill string, stress and deformation of bits, but also to predict the side force and direction of bits and to determine the size of the drill string deformation. It can also provide references to BHA design and the selection of sidetracking operation parameters.

Classification of Tight Sandstone Reservoir Based on the Conventional Logging

2014 ◽  
Vol 633-634 ◽  
pp. 526-529 ◽  
Author(s):  
Xiao Ling Xiao ◽  
Jia Li Cui ◽  
Yu Peng Zhang ◽  
Xiang Zhang ◽  
Han Wu
Keyword(s):  
Support Vector Machine ◽  
Oil And Gas ◽  
Identification Accuracy ◽  
Support Vector ◽  
Tight Sandstone ◽  
Oil And Gas Exploration ◽  
Unconventional Oil ◽  
Unconventional Oil And Gas ◽  
Sandstone Reservoir

With the increasing social demand for oil and gas resources, the exploration and development of unconventional oil and gas reservoirs will pay more and more attention. Tight sandstone reservoir classification is one of the important tasks in the research of unconventional oil and gas exploration and development.Limitations exist in tight sandstone reservoir classification by various conventional logging.A method for the classification of tight sandstone reservoir based on support vector machine is presented in this paper, combining with the core data and flow unit to establish the reservoir classification standard. Tight sandstone reservoirs of no coring wells are classified based on the model made by support vector machine using conventional logging.The application results show that this method has high suitability and identification accuracy.

Risk In Exploration And Production - Eliminating Risk Is Not An Option - It's How You Manage It That Matters!

2015 ◽  
Author(s):  
Lars SØrum
Keyword(s):  
Oil And Gas ◽  
Oil And Gas Development ◽  
Oil And Gas Exploration ◽  
Risk Levels ◽  
The Us ◽  
Comparative Advantages ◽  
Exploration And Production ◽  
Unconventional Oil And Gas ◽  
Below Ground ◽  
And Performance

Abstract The paper aims to provide insights as to what risk elements are observed in the US shale and tight oil and gas development and how they sit in a European setting. In doing so the paper explores the comparative advantages in prescriptive and performance based approaches for shale risk management and through discussing consequence based vs. risk based philosophies. The author uses metrics for below ground risks to compare risk levels. In doing so the paper aim to qualify what what is perceived as risk and what risks are measured in unconventional oil and gas exploration and production.

scholarly journals Study on the Upper Paleozoic Source Rocks in Southwestern Henan, China

2021 ◽  
Vol 257 ◽  
pp. 03010
Author(s):  
Fengyu Sun ◽  
Gaoshe Cao ◽  
Zhou Xing
Keyword(s):  
Carbonate Rock ◽  
Oil And Gas ◽  
Lower Layer ◽  
Sedimentary Environment ◽  
Source Rocks ◽  
Oil And Gas Exploration ◽  
Potential Source ◽  
Upper Paleozoic ◽  
Unconventional Oil And Gas ◽  
Coal Rock

The Upper Paleozoic strata in Southwestern Henan have good prospects for unconventional oil and gas exploration. This paper takes the Upper Paleozoic source rocks in the Yuzhou area and the Pingdingshan area in Southwestern Henan as the research object, and tests 107 samples from the Upper Paleozoic coal rock, mudstone and carbonate rock. Combined with the sedimentary environment background, the Upper Paleozoic source rocks in Southwestern Henan are comprehensively evaluated. The results show that the Upper Paleozoic source rocks in Southwestern Henan, including coal rocks, mudstone and carbonate rocks, can be used as potential source rocks. Vertically, the source rocks are continuously distributed in the lower layer below the sandstone of Shanxi Formation. The Dazhan sandstone is only locally developed; the distribution of Upper Paleozoic source rocks in Southwestern Henan is mainly related to the Late Paleozoic transgression.

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