scholarly journals A New Logging-While-Drilling Method for Resistivity Measurement in Oil-Based Mud

Sensors ◽  
2020 ◽  
Vol 20 (4) ◽  
pp. 1075
Author(s):  
Yongkang Wu ◽  
Baoping Lu ◽  
Wei Zhang ◽  
Yandan Jiang ◽  
Baoliang Wang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Measurement Accuracy ◽  
Resistivity Measurement ◽  
Well Logging ◽  
Inductive Coupling ◽  
Detection Depth ◽  
Coupling Principle ◽  
Logging While Drilling ◽  
Measurement Path ◽  
Ac Measurement

Resistivity logging is an important technique for identifying and estimating reservoirs. Oil-based mud (OBM) can improve drilling efficiency and decrease operation risks, and has been widely used in the well logging field. However, the non-conductive OBM makes the traditional logging-while-drilling (LWD) method with low frequency ineffective. In this work, a new oil-based LWD method is proposed by combining the capacitively coupled contactless conductivity detection (C4D) technique and the inductive coupling principle. The C4D technique is to overcome the electrical insulation problem of the OBM and construct an effective alternating current (AC) measurement path. Based on the inductive coupling principle, an induced voltage can be formed to be the indirect excitation voltage of the AC measurement path. Based on the proposed method, a corresponding logging instrument is developed. Numerical simulation was carried out and results show that the logging instrument has good measurement accuracy, deep detection depth and high vertical resolution. Practical experiments were also carried out, including the resistance box experiment and the well logging experiment. The results of the resistance box experiment show that the logging instrument has good resistance measurement accuracy. Lastly, the results of the well logging experiment indicate that the logging instrument can accurately reflect the positions of different patterns on the wellbore of the experimental well. Both numerical simulation and practical experiments verify the feasibility and effectiveness of the new method.

Development of a directional resistivity logging-while-drilling tool using a joint-coil antenna and its geosteering applications

Geophysics ◽  
2018 ◽  
Vol 83 (5) ◽  
pp. D165-D171
Author(s):  
Zhong Wang ◽  
Huaping Wang ◽  
Treston Davis ◽  
Jing Li ◽  
Suming Wu ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Gas Production ◽  
Voltage Response ◽  
Drilling Tool ◽  
Detection Depth ◽  
Logging While Drilling ◽  
Resistivity Logging ◽  
Coil Antenna ◽  
Production Zone ◽  
Distance To The Boundary

Geosteering is a key technique to increase oil- and gas-production rates, especially within a thin reservoir layer. The purpose of geosteering in the production zone is to keep the drilling path in oil- and gas-bearing reservoirs. To keep the drilling system inside the production zone, downhole sensors must be able to detect bed boundaries, which include identifying the boundary location with respect to the sensor and the boundary distance from the sensor. We have developed a directional resistivity logging-while-drilling (LWD) tool for geosteering applications. The directional LWD tool is equipped with a joint-coil antenna composed of an axially polarized coil Rz connected in series with two transversely polarized coils Rx. During a revolution around the axis of the tool, the voltage of the axial coil VRz, voltage of the transverse coils VRx, and tool face angle [Formula: see text], which indicates the boundary direction, can be extracted through curve fitting the total voltage response of the joint-coil antenna. The distance to the boundary can be derived from a 1D inversion. The LWD tool has been tested in several reservoirs in China, and it has a demonstrated capability to provide reliable and accurate estimations of the boundary direction and distance. Field data indicate that the boundary detection depth can reach 2.1 and 1.7 m when the tool is in a sand and shale formation. Using wireline-logging data from surrounding wells as reference, deviations between the reference and the measured distance to the boundary are within 0.2 m.

scholarly journals Numerical simulation and dimension reduction analysis of electromagnetic logging while drilling of horizontal wells in complex structures

2020 ◽  
Vol 17 (3) ◽  
pp. 645-657
Author(s):  
Zhen-Guan Wu ◽  
Shao-Gui Deng ◽  
Xu-Quan He ◽  
Runren Zhang ◽  
Yi-Ren Fan ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Dimension Reduction ◽  
Horizontal Wells ◽  
Complex Structures ◽  
Logging While Drilling

Frequency-domain simulation of logging-while-drilling borehole sonic waveforms

Geophysics ◽  
2014 ◽  
Vol 79 (2) ◽  
pp. D99-D113 ◽  
Author(s):  
Paweł J. Matuszyk ◽  
Carlos Torres-Verdín
Keyword(s):  
Numerical Simulation ◽  
Wave Propagation ◽  
Frequency Domain ◽  
Internal Structure ◽  
Adaptive Finite Element Method ◽  
Computational Domain ◽  
Mechanical Filter ◽  
Logging While Drilling ◽  
Sonic Logging

Numerical simulation of sonic logging-while-drilling (LWD) borehole measurements is challenging because of significant wave propagation effects due to the massive drilling collar occupying a large portion of the borehole. In addition, the internal structure of the LWD tool can have a significant impact on the measured dispersions of Stoneley and quadrupole modes. The collar is typically constructed with a set of inner periodic grooves, which act as a mechanical filter to attenuate undesirable collar modes. Reliable numerical simulation and interpretation of LWD sonic waveforms requires that all features and dimensions of the drilling collar be included in the simulation model. Furthermore, the presence of the drilling collar can prompt numerical instabilities due to backward propagating modes in the perfectly matched layer (PML) commonly used to truncate the computational domain. This problem can be circumvented with the implementation of artificial viscoelastic attenuation in the collar whenever the simulations are intended to reproduce only wave propagation within the surrounding rock formations. In addition, reliable modeling of borehole wave propagation in the presence of high contrasts in material properties and the internal structure of the LWD collar requires a numerical method capable of accurately and stably resolving all spectral scales present in the model. We implemented an automatic [Formula: see text]-adaptive finite-element method in the frequency domain combined with a PML technique to simulate LWD sonic logging measurements. Examples of the application verified the accuracy and reliability of the simulated borehole and formation propagation modes in the presence of casing and internal structures in the LWD collar. The presence of steel casing and quality of casing/formation bond significantly influence the propagation modes excited in a borehole. However, it is still possible to estimate the formation shear slowness using monopole and quadrupole sources regardless of the quality of cement bond in fast formations. Assessment of the formation compressional slowness was significantly impeded by the strong pipe mode. Estimation of formation shear slowness in slow formations is practically impossible due to the presence of casing and a strong annulus mode when the quality of casing bond is poor.

scholarly journals Research on the normalisation method of logging curves: taking XJ Oilfield as an example

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Chang Mingyang ◽  
Deng Rui ◽  
Wang Haijiang ◽  
Xie Bibo ◽  
Zhao Zhongliang
Keyword(s):  
Operation Mode ◽  
Systematic Errors ◽  
Well Logging ◽  
Calibration Standard ◽  
Frequency Histogram ◽  
Geological Information ◽  
Logging While Drilling ◽  
Mean Variance ◽  
Normalisation Method

Abstract During the long-term exploration and development of the oilfield, it is difficult to ensure that all well logging curves are measured by the same type of instrument, the same calibration standard and the same operation mode, For different wells, there must be systematic errors caused by these reasons. Therefore, in addition to environmental correction, it is necessary to standardise logging curves. In XJ oilfield, three logging companies use wireline logging and logging while drilling to complete logging, in multi-well logging interpretation. To eliminate the systematic errors of different measuring tools, to maximise the geological information reflected by logging curves, and to make logging interpretation follow the same standard as much as possible, it is necessary to standardise the logging curve in the whole oilfield. This article takes the standardisation of well 106 in XJ oilfield as an example, the standardisation of different methods was compared, the method of combining frequency histogram and mean variance is better.

scholarly journals Numerical simulation of pressure pulsation effects of a snubber in a CNG station for increasing measurement accuracy

2019 ◽  
Vol 13 (1) ◽  
pp. 642-663 ◽  
Author(s):  
Mahmood Farzaneh-Gord ◽  
Mostafa Faramarzi ◽  
Mohammad Hossein Ahmadi ◽  
Meisam Sadi ◽  
Shahaboddin Shamshirband ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Measurement Accuracy ◽  
Pressure Pulsation

Numerical Simulation of Rf Resonant Antenna-Plasma Inductive Coupling in Planar Geometry

2017 ◽  
Author(s):  
Antonio DrAngola ◽  
Renato Zaffina ◽  
Ivo Furno ◽  
Alan A. Howling ◽  
Remy Jacquier ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Inductive Coupling ◽  
Planar Geometry
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