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Acta Geologica Sinica(English Edition) 2019年第3期93卷 718-730页

作者： YIN Qifeng TAO Pengfei ZHENG Shuo HE Qing AN Yanfei GUO Quanshi School of Resources and Environmental Engineering Anhui UniversityHefei 230601China Sinopec Geophysical Research Institute Nanjing 211103China

downhole microseismic data has the significant advantages of high signal-to-noise ratio and well-developed P and S waves and the core component of microseismic monitoring is microseismic event location associated with hydraulic fracturing in a relatively high confidence level and accuracy.In this study,we present a multidimensional DIRECT inversion method for microseismic locations and applicability tests over modeling data based on a downhole microseismic monitoring system.Synthetic tests inidcate that the objective function of locations can be defined as a multi-dimensional matrix space by employing the global optimization DIRECT algorithm,because it can be run without the initial value and objective function derivation,and the discretely scattered objective points lead to an expeditious contraction of objective functions in each dimension.This study shows that the DIRECT algorithm can be extensively applied in real downhole microseismic monitoring data from hydraulic fracturing completions.Therefore,the methodology,based on a multidimensional DIRECT algorithm,can provide significant high accuracy and convergent efficiency as well as robust computation for interpretable spatiotemporal microseismic evolution,which is more suitable for real-time processing of a large amount of downhole microseismic monitoring data.

关键词： unconventional oil and gas reservoir downhole microseismic monitoring source location DIRECT algorithm

OFDM Wireless downhole Transmission Systems and Proposed SLM Method for PAPR Reduction

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Communications and Network 2014年第1期6卷 9-14页

作者： Renze Luo Yupu Dang Rui Li Jiao Yang Department of Well Tech China Oilfield Services Limited Beijing China State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum University Chengdu China

At present, mud pulse transmission systems are widely used in downhole data transmission. But the systems are very low in transmission efficiency, only 5-10 bits/s, with very large anti-inter-symbol-interference (ISI). It cannot meet high requirements for high-speed transmission of modern logging system. The development of communication technology has laid some foundation for this requirement. For this purpose, the Orthogonal Frequency Division Multiplexing (OFDM) Wireless downhole Transmission Systems are proposed for the first time because of their high transmission rate, anti-inter-symbol-interference (ISI), and high spectral efficiency, etc. Due to non-linear power amplifier (PA) of logging systems with limited dynamic range, the drawbacks of high peak-average power ratio (PAPR) may outweigh all the potential benefits of OFDM wireless downhole transmission systems. Selective mapping (SLM) method can reduce the PAPR of OFDM logging signals without distortion. But at the receiver, the conventional SLM method needs exact bits of side information (SI) to recover the data signal. The probability of erroneous SI detection has a significant influence on the error performance of the system. And individual transmissions of SI result in the reduction of bandwidth efficiency. To restore the exact data signal, our scheme codes the SI bits by linear block codes (LBC), and is easily decoded by syndrome decoding. And then the coding SI bits are superimposed onto the logging signals to omit SI bits transmission. The theory and simulation results show that the proposed method has better performance than the conventional one. Accordingly, the OFDM wireless downhole transmission systems can tackle the high PAPR problem, and highten the transmission rate of logging signals.

关键词： Orthogonal Frequency Division Multiplexing Wireless downhole Transmission Systems Orthogonal Frequency Division Multiplexing (OFDM) Logging While Drilling (LWD) Peak-to-Average Power Ratio (PAPR) Selected Mapping (SLM)

Numerical simulation of surface and downholedeformation induced by hydraulic fracturing

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Applied Geophysics 2014年第1期11卷 63-72,116,117页

作者：何怡原张保平段玉婷薛承瑾闫鑫何川胡天跃北京大学地球与空间科学学院北京100871 中国石化石油工程技术研究院北京100101

Tiltmeter mapping technology infers hydraulic fracture geometry by measuringfracture-induced rock deformation, which recorded by highly sensitive tiltmeters placed atthe surface and in nearby observation wells. By referencing Okada＇s linear elastic theory andGreen＇s function method, we simulate and analyze the surface and downhole deformationcaused by hydraulic fracturing using the homogeneous elastic half-space model and layeredelastic model. Simulation results suggest that there is not much difference in the surfacedeformation patterns between the two models, but there is a significant difference in thedownhole deformation patterns when hydraulic fracturing penetrates a stratum. In suchcases, it is not suitable to assume uniform elastic half-space when calculating the downholedeformation. This work may improve the accuracy and reliability of the inversion results oftiltmeter monitoring data.

关键词： Hydraulic fracturing, surface tilt field, downhole tilt field, layered model,numerical simulation

Validity of the Refraction Microtremors (ReMi) Method for Determining Shear Wave Velocities for Different Soil Types in Egypt

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International Journal of Geosciences 2011年第4期2卷 530-540页

作者： Mohamed Ahmed Gamal Satish Pullammanappallil 不详

The Refraction Microtremor (ReMi) method is being used around the world by the geotechnical and geophysical community to determine shear-wave velocities. This is due to its faster, less expensive and accurate determination of shear wave velocities, when compared to other methods used. Unlike standard crosshole and downhole techniques, ReMi does not require any drilling. It eliminates the problem of shear-wave source and quiet site that are pre-requisites for good seismic refraction surveys. In this paper we present refraction microtremors (ReMi) measurements done at sites underlain by different soil types in Egypt. The ReMi data were collected using standard refraction equipment employing 12, 24 or 48 channels. We used deep oceanographic noise and ambient noise including energy from power generators, pile drivers and traffic. The data were processed using the SeisOpt? ReMi? (? Optim, Inc.) software to reveal one-dimensional shear-wave velocity structures beneath the arrays. To access the validity of the method for the Egyptian soils, the shear-wave profiles obtained from the ReMi measurements were compared to downhole and crosshole data for different soils. Comparisons demonstrate the robustness of the ReMi technique for obtaining shear-wave velocities for different soil types in Egypt.

关键词： Refraction Microtremors ReMi Crosshole downhole Shear Wave Egypt

Modeling of Asphaltene Grading in Oil Reservoirs

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Natural Resources 2010年第1期1卷 19-27页

作者： Julian Y. Zuo Oliver C. Mullins Chengli Dong Dan Zhang 不详

Reservoir fluids frequently reveal complex phase behaviors in hydrocarbon columns owing to the effects of gravity, thermal diffusion, biodegradation, active charging, water washing, seals leaking, and so on. In addition, the formation compartmentalization often causing discontinuous distributions of fluid compositions and properties makes the proper fluid characterization and reservoir architecture even more challenging yet compelled. The recognition of compositional grading and flow barriers becomes a key to accurate formation evaluation in a cost effective manner. downhole fluid analysis (DFA) of asphaltene gradients provides an excellent method to delineate the complexity of black oil columns. In this paper, a methodology was developed to estimate downhole asphaltene variations with depths using an equation-of-state (EOS) approach coupled with DFA measurements. DFA tools were used to determine fluid compositions of CO2, C1, C2, C3-C5, C6+, gas-oil ratio (GOR), density and the coloration (optical density) associated with asphaltene contents at downhole conditions. The delumping and characterization procedures proposed by Zuo et al. (2008) were employed to obtain the detailed compositions excluding asphaltenes. In addition, a molar mass distribution of asphaltenes was described by a three-parameter Gamma probability function. The Gaussian quadrature method was used to generate asphaltene pseudocomponents. Five pseudocomponents were employed to represent the normal asphaltene nanoaggregates. Asphaltene distributions in oil columns were computed by tuning the molar mass of asphaltene nanoaggregates against the DFA coloration logs at a reference depth. The methodology was successfully applied to investigate black oil reservoir connectivity (or flow barriers) for offshore field cases. The analysis results were consistent with the subsequent production data and analytical chemistry. Furthermore, for simplicity, it is reasonable to assume that asphaltenes have average properties such as molar mass in entire oil column

关键词： Reservoir Connectivity Asphaltene Gradients Equations of State downhole Fluid Analysis

Application of Active Power Curve of Motor in Situ

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China Oil & Gas 1996年第3期3卷 171-173页

作者： Wang Dexi(The Sixth Oil-production Plant of Daqing Petroleum Administration) The Sixth Oil-production Plant of Daqing Petroleum Administration

ＡｐｐｌｉｃａｔｉｏｎｏｆＡｃｔｉｖｅＰｏｗｅｒＣｕｒｖｅｏｆＭｏｔｏｒｉｎＳｉｔｕＷａｎｇＤｅｘｉ（ＴｈｅＳｉｘｔｈＯｉｌ－ｐｒｏｄｕｃｔｉｏｎＰｌａｎｔｏｆＤａｑｉｎｇＰｅｔｒｏｌｅｕｍＡｄｍｉｎｉｓｔｒａｔｉｏ... 详细信息

ＡｐｐｌｉｃａｔｉｏｎｏｆＡｃｔｉｖｅＰｏｗｅｒＣｕｒｖｅｏｆＭｏｔｏｒｉｎＳｉｔｕＷａｎｇＤｅｘｉ（ＴｈｅＳｉｘｔｈＯｉｌ－ｐｒｏｄｕｃｔｉｏｎＰｌａｎｔｏｆＤａｑｉｎｇＰｅｔｒｏｌｅｕｍＡｄｍｉｎｉｓｔｒａｔｉｏｎ）Ｋｅｙｗｏｒｄｓ：Ｗｅｌｌｐｕ...

关键词： Well pumping unit downhole status diagnosis Monitoring Pump performance.

海床CPT和井下CPT在砂土中贯入机理差异研究

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海洋工程 2016年第2期34卷 35-40页

作者：李飒戴旭周杨锐蒋宝凡天津大学建工学院岩土所天津300072 中海油服物探事业部天津300456

海洋石油建设中的一个关键环节是对有关海域的工程地质条件作出准确评价。海上原位静力触探(CPT)是主要的原位勘察手段,与陆地CPT不同,其贯入方式主要有Seabed和downhole两种形式。这两种CPT由于贯入方式不同,所得到的锥端阻力存在一定... 详细信息

海洋石油建设中的一个关键环节是对有关海域的工程地质条件作出准确评价。海上原位静力触探(CPT)是主要的原位勘察手段,与陆地CPT不同,其贯入方式主要有Seabed和downhole两种形式。这两种CPT由于贯入方式不同,所得到的锥端阻力存在一定的差异。采用有限元方法对这两种形式的CPT锥端阻力和贯入模式进行计算分析。研究显示,CPT入土过程中,周围土体存在两种不同位移状态,即滑动状态和排挤状态。在入土初期,土体以滑动状态为主,土体中竖向应力随贯入深度的增加而递增。在入土一定深度以后,土体的排挤状态占主导地位,竖向应力变化趋于平稳。这两种位移状态的相互转化解释了Seabed CPT和downhole CPT实测数据之间的差异。在贯入深度较大时,Seabed CPT受排挤状态控制,而downhole CPT仍然受滑动状态的影响。

关键词： Seabed CPT downhole CPT 砂土贯人机理

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减小扭矩的旋转式井下测井仪

国外测井技术 2018年第3期39卷 7-7页

Systems and methods for reducing torque on a rotating downhole logging tool are provided.In one embodiment,a downhole logging tool is provided.The downhole logging tool may include a support element,which may include a hollow cavity.The support element may be configured to rotate about an axis when the support element is inserted in a well,and the hollow cavity may be configured to permit fluid flow through the support element when the support element is in the well.Furthermore,the downhole logging tool may include a first fairing portion,which may include a first sensor to obtain measurements in the well.Additionally,the first fairing portion may be configured to form a revolution surface associated with a portion of the support element to reduce fluidic resistance of the rotating support element.

关键词： rotating downhole logging tool Furthermore