This paper proposes a rapid means of identifying clay type and quantifying clay content from new template crossplots that compare magnetic susceptibility measurements with standard borehole well log data. The template...This paper proposes a rapid means of identifying clay type and quantifying clay content from new template crossplots that compare magnetic susceptibility measurements with standard borehole well log data. The templates are similar in format to standard industry charts, but have a number of advantages over the commonly used charts. Laboratory measurements of magnetic susceptibility on core samples and drill cuttings have recently shown strong correlations with key petrophysical parameters, particularly clay content and fluid permeability [1] [2]. A new template crossplot between magnetic susceptibility and borehole spectral gamma ray log data can firstly help to quickly identify the types of clay present in the formation. Additional new template crossplots between magnetic susceptibility and borehole bulk density data allow the mineral contents and porosities of binary mixtures of clay minerals and matrix minerals (such as illite clay + quartz) to be rapidly quantified. The templates can use ambient (room temperature) magnetic susceptibility data from measurements on core samples or drill cuttings in the laboratory or at the wellsite. Furthermore, the paper shows how the templates can potentially be extended to utilize borehole magnetic susceptibility data for in situ estimations of the type and content of clay. This requires accounting for the temperature dependence of the magnetic susceptibility of paramagnetic minerals (such as illite clay), which varies with depth in a borehole. Whilst borehole magnetic susceptibility measurements are rarely part of standard well logging operations, they could be a potentially useful tool for in situ clay type and content quantification, which in turn can help predict fluid permeability.展开更多
The vector transformation and pole reduction from the total-field anomaly are signifi cant for the interpretation.We examined these industry-standard processing procedures in the Fourier domain.We propose a novel iter...The vector transformation and pole reduction from the total-field anomaly are signifi cant for the interpretation.We examined these industry-standard processing procedures in the Fourier domain.We propose a novel iteration algorithm for regional magnetic anomalies transformations to derive the vertical-component data from the total-field measurements with the variation in the core-fi eld direction over the region.Additionally,we use the same algorithm to convert the calculated vertical-component data into the corresponding data at the pole and realize the processing of diff erential reduction to the pole(DRTP).Unlike Arkani-Hamed’s DRTP method,the two types of iterative algorithms have the same forms,and DRTP is realized by implementing this algorithm twice.The synthetic model’s calculation results show that the method has high accuracy,and the fi eld data processing confi rms its practicality.展开更多
In this paper, the solution of Chebyshev equation with its argument being greater than 1 is obtained. The initial value of the derivative of the solution is the expression of magnetization, which is valid for any spin...In this paper, the solution of Chebyshev equation with its argument being greater than 1 is obtained. The initial value of the derivative of the solution is the expression of magnetization, which is valid for any spin quantum number S. The Chebyshev equation is transformed from an ordinary differential equation obtained when we dealt with Heisenberg model, in order to calculate all three components of magnetization, by many-body Green＇s function under random phase approximation. The Chebyshev functions with argument being greater than 1 are discussed. This paper shows that the Chebyshev polynomials with their argument being greater than 1 have their physical application.展开更多
Borehole nuclear magnetic resonance(NMR)is a powerful technology to characterize the petrophysical properties of underground reservoirs in the petroleum industry.The rising complexity of oil and gas exploration and de...Borehole nuclear magnetic resonance(NMR)is a powerful technology to characterize the petrophysical properties of underground reservoirs in the petroleum industry.The rising complexity of oil and gas exploration and development objectives,as well as the novel application contexts of underground reservoirs,have led to increasingly demanding requirements on borehole NMR technology including instrument design and related processing methods.This mini review summarizes the advances and applications of borehole NMR instruments along with some future possibilities.It may be helpful for researchers and engineers in the petroleum industry to understand the development status and future trends of borehole NMR technology.展开更多
When one wants to calculate all the three components of magnetization of Heisenberg model under random phase approximation, at least one of the components should be the solution of an ordinary differential equation. I...When one wants to calculate all the three components of magnetization of Heisenberg model under random phase approximation, at least one of the components should be the solution of an ordinary differential equation. In this paper such an equation is established. It is argued that the general expressions of magnetization for any spin quantum number S suggested before are the solution of the ordinary differential equation.展开更多
Detailed rock magnetic and paleomag- netic studies have been undertaken on borehole EY02-2 (70m in length) in the southern Yellow Sea (SYS). The main Curie point revealed by magnetic susceptibility-temperature (k-T) c...Detailed rock magnetic and paleomag- netic studies have been undertaken on borehole EY02-2 (70m in length) in the southern Yellow Sea (SYS). The main Curie point revealed by magnetic susceptibility-temperature (k-T) curve is 580―600℃ indicating magnetite dominance. The hysteresis loop parameters show large variation of magnetic minera size in different sedimentary contexts: it is larger in subtidal sediment than in terrigenous sediment and even larger than in shallow sea sediment. This trend is correlative with distance to sediment source and dynamic strength. Magnetostratigraphic results show that the M/B polarity boundary (MBPB) is at 63.29m and there are at least 7 polarity transitions (Nr1-7) in Brunhes chron that can be tentatively correlated with 6 named polarity reversals. Three positive polarity reversals occur in late Matuyama chron and the early two may be the record of Kamikatsura happening in 886±3 kaB.P. Magnetic susceptibility (MS) and sediment grain size behave so differently in some sedimentary facies that certain big environmenta changes can be clearly revealed. Generally, the MS and grain size of subtidal and terrigenous sediments are larger than shallow sea sediments and MS value around 10×10?5SI and mean grain size of 7Φ seems to be indicators of shallow sea sediments of deep water depth. However, the frequently used excellen climatic proxies such as MS and grain size in loess and deep sea sediments fail to record such climatic cycles revealed by oxygen isotope in continental seaThe various sediment sources, sedimentation dy- namic and their complex changes between glacial and interglacial periods should be the cause of fail- ure.展开更多
文摘This paper proposes a rapid means of identifying clay type and quantifying clay content from new template crossplots that compare magnetic susceptibility measurements with standard borehole well log data. The templates are similar in format to standard industry charts, but have a number of advantages over the commonly used charts. Laboratory measurements of magnetic susceptibility on core samples and drill cuttings have recently shown strong correlations with key petrophysical parameters, particularly clay content and fluid permeability [1] [2]. A new template crossplot between magnetic susceptibility and borehole spectral gamma ray log data can firstly help to quickly identify the types of clay present in the formation. Additional new template crossplots between magnetic susceptibility and borehole bulk density data allow the mineral contents and porosities of binary mixtures of clay minerals and matrix minerals (such as illite clay + quartz) to be rapidly quantified. The templates can use ambient (room temperature) magnetic susceptibility data from measurements on core samples or drill cuttings in the laboratory or at the wellsite. Furthermore, the paper shows how the templates can potentially be extended to utilize borehole magnetic susceptibility data for in situ estimations of the type and content of clay. This requires accounting for the temperature dependence of the magnetic susceptibility of paramagnetic minerals (such as illite clay), which varies with depth in a borehole. Whilst borehole magnetic susceptibility measurements are rarely part of standard well logging operations, they could be a potentially useful tool for in situ clay type and content quantification, which in turn can help predict fluid permeability.
基金supported by the National Key R&D Program of China (No. 2017YFC0602000)the China Geological Survey Project (Nos. DD20191001 and DD20189410)。
文摘The vector transformation and pole reduction from the total-field anomaly are signifi cant for the interpretation.We examined these industry-standard processing procedures in the Fourier domain.We propose a novel iteration algorithm for regional magnetic anomalies transformations to derive the vertical-component data from the total-field measurements with the variation in the core-fi eld direction over the region.Additionally,we use the same algorithm to convert the calculated vertical-component data into the corresponding data at the pole and realize the processing of diff erential reduction to the pole(DRTP).Unlike Arkani-Hamed’s DRTP method,the two types of iterative algorithms have the same forms,and DRTP is realized by implementing this algorithm twice.The synthetic model’s calculation results show that the method has high accuracy,and the fi eld data processing confi rms its practicality.
基金The project supported by the State Key Project of Fundamental Research of China under Grant No. G2000067101
文摘In this paper, the solution of Chebyshev equation with its argument being greater than 1 is obtained. The initial value of the derivative of the solution is the expression of magnetization, which is valid for any spin quantum number S. The Chebyshev equation is transformed from an ordinary differential equation obtained when we dealt with Heisenberg model, in order to calculate all three components of magnetization, by many-body Green＇s function under random phase approximation. The Chebyshev functions with argument being greater than 1 are discussed. This paper shows that the Chebyshev polynomials with their argument being greater than 1 have their physical application.
基金“The Strategic Cooperation Technology Projects of CNPC and CUP(Grant Number ZLZX2020-03)”“China Postdoctoral Science Foundation(Grant Number 2021M700172)”.
文摘Borehole nuclear magnetic resonance(NMR)is a powerful technology to characterize the petrophysical properties of underground reservoirs in the petroleum industry.The rising complexity of oil and gas exploration and development objectives,as well as the novel application contexts of underground reservoirs,have led to increasingly demanding requirements on borehole NMR technology including instrument design and related processing methods.This mini review summarizes the advances and applications of borehole NMR instruments along with some future possibilities.It may be helpful for researchers and engineers in the petroleum industry to understand the development status and future trends of borehole NMR technology.
基金the State Key Project of Fundamental Research of China under
文摘When one wants to calculate all the three components of magnetization of Heisenberg model under random phase approximation, at least one of the components should be the solution of an ordinary differential equation. In this paper such an equation is established. It is argued that the general expressions of magnetization for any spin quantum number S suggested before are the solution of the ordinary differential equation.
基金supported by the National Natural Science Foundation of China(Grant Nos.40431002 and 40574029)Youth Foundation of State 0ceanic Administration(Grant No.2004303).
文摘Detailed rock magnetic and paleomag- netic studies have been undertaken on borehole EY02-2 (70m in length) in the southern Yellow Sea (SYS). The main Curie point revealed by magnetic susceptibility-temperature (k-T) curve is 580―600℃ indicating magnetite dominance. The hysteresis loop parameters show large variation of magnetic minera size in different sedimentary contexts: it is larger in subtidal sediment than in terrigenous sediment and even larger than in shallow sea sediment. This trend is correlative with distance to sediment source and dynamic strength. Magnetostratigraphic results show that the M/B polarity boundary (MBPB) is at 63.29m and there are at least 7 polarity transitions (Nr1-7) in Brunhes chron that can be tentatively correlated with 6 named polarity reversals. Three positive polarity reversals occur in late Matuyama chron and the early two may be the record of Kamikatsura happening in 886±3 kaB.P. Magnetic susceptibility (MS) and sediment grain size behave so differently in some sedimentary facies that certain big environmenta changes can be clearly revealed. Generally, the MS and grain size of subtidal and terrigenous sediments are larger than shallow sea sediments and MS value around 10×10?5SI and mean grain size of 7Φ seems to be indicators of shallow sea sediments of deep water depth. However, the frequently used excellen climatic proxies such as MS and grain size in loess and deep sea sediments fail to record such climatic cycles revealed by oxygen isotope in continental seaThe various sediment sources, sedimentation dy- namic and their complex changes between glacial and interglacial periods should be the cause of fail- ure.
