A Multi-level Approach for Complex Fault Isolation Based on Structured Residuals

In industrial processes,there exist faults that have complex effect on process variables.Complex and simple faults are defined according to their effect dimensions.The conventional approaches based on structured residuals cannot isolate complex faults.This paper presents a multi-level strategy for complex fault isolation.An extraction procedure is employed to reduce the complex faults to simple ones and assign them to several levels.On each level,faults are isolated by their different responses in the structured residuals.Each residual is obtained insensitive to one fault but more sensitive to others.The faults on different levels are verified to have different residual responses and will not be confused.An entire incidence matrix containing residual response characteristics of all faults is obtained,based on which faults can be isolated.The proposed method is applied in the Tennessee Eastman process example,and the effectiveness and advantage are demonstrated.

Exploration Strategies for Complex Fault Block Reservoirs in the Subei Basin

The geological background of the Subei basin is that of small relief subsidence, low geothermal gradient, multi-sedimentary hiatuses, intense reconstruction of the basin, frequent magmatic activity, and a unique combination of source rock and reservoir. This geological background resulted in characteristics such as many small fault blocks, multiple oil-bearing formations, scattered oil distribution, mini- to small-sized reservoirs, and difficulties in exploration. Aimed at such characteristics, an effective exploration strategy was adopted, and the oil reserves, production and economic benefits of the Jiangsu oilfield were significantly increased. This exploration strategy included understanding the hydrocarbon generation mechanism of source rocks, progressive evaluation of oil resources, comprehensive research on the faulted systems, the distribution of oil reservoirs and their controlling factors. The techniques used included integration of acquisition, processing and interpretation with 3-D seismics as the core technology, trap description and evaluation, directional drilling and cluster drilling, integration of cuttings logging, gas chromatographic logging and geochemical logging, and integration of early reservoir description and progressive exploration and development. This strategy could be guidance for other complex fault blocks.

Boundary integral equations for dynamic rupture propagation on vertical complex fault system in half-space:Theory

The boundary integral equation method （BIEM） is now widely used in numerical studies on earthquake rupture dynamics, and is proved to be a powerful tool to deal with problems on complex fault system. However, since this method heavily lies on the specific forms of Green＇s function and only the Green＇s function in full-space has a closed analytic expression, it is usually limited to a full-space medium. In this study, as a first step to extend this method to an arbitrary complex fault system in half-space, the boundary integral equations （BIEs） for dynamic strike-slip on vertical complex fault system in half-space are derived based on exact Green＇s function for isotropic and homogeneous half-space. Effect of the geometry of the complex fault system are dealt with carefully. Final BIEs is composed of two parts： contribution from full-space, which has been thoroughly investigated by Aochi and his co-workers by using the Green＇s function for full-space, and that from free surface, which is studied in detail in this study.

Farewell faults in complex fault blocks with multi-technological integration

In the middle and second half of oilfield development,further exploration and development of petroleum reservoirs in complex fault blocks are major tasks.Based on the characteristics of fully developed farewell faults in the Wenweigu oil field and the data from 3D earthquakes,RFT,HDT and other techniques,farewell faults and their distribution were identified.Conformation of the fault blocks has been provided and the precision of describing the farewell faults improved.Research technology of farewell faults has applied these methods in this region.

Vertical dominant migration channel and hydrocarbon migration in complex fault zone, Bohai Bay sag, China

The quantitatively/semi-quantitatively formation conditions of vertical dominant hydrocarbon migration pathways were analyzed based on the big data analysis of petroleum geological parameters of complex fault Zone zone in the central-south Bohai Bay. According to this condition, the vertical dominant migration pathway and its charge points/segments are searched through structural modeling assistant analysis in the East Sag of Huanghekou. Under the constraints of charge points/segments, numerical simulation of hydrocarbon charge and migration is carried out to successfully predict hydrocarbon migration pathways and hydrocarbon enrichment blocks in shallow layers of complex fault zone. The main results are as follows:(1) The hydrocarbon charge in shallow layers of the active fault zone is differential, the charge points/sections of vertical dominant migration pathways are the starting points of shallow hydrocarbon migration and are very important for the hydrocarbon migration and accumulation in the shallow layers.(2) Among the shallow faults, those cutting the deep transfer bins or deep major migration pathways, with fault throw of more than 80 m in the accumulation period and the juxtaposition thickness between fault and caprock of the deep layers of less than 400 m are likely to be vertical dominant migration pathways in the sag area.(3) By controlling the vertical dominant migration pathways and charging points/segments in carrier layer, Neo-tectonic movement caused the differential hydrocarbon accumulation in the complex fault zone. The research results are of great significance for the fine exploration of the complex fault zone.

A new numerical well testing approach: Application to characterization of complex fault structures

Fluid flow in hydrocarbon reservoirs and consequently optimum scenario for hydrocarbon production,is heavily influenced by reservoir heterogeneities.Faults are one of the most common types of heterogeneity found in reservoirs.Leaky faults,baffles(limited extent faults)and complex multiple fault geometries are among the most complicated and important types of faults that are difficult to characterize.Leaky faults,unlike the sealing faults,are in partial communication with other portions of the reservoir.Because of faults'effect on reservoir connectivity and possible infill drilling plan for accessing all parts of the reservoirs,possible communication across the fault must be precisely modeled.In order to detect the effect of a fault on communication within the reservoir,we need to analyze dynamic data.There are a few analytical methods for modelling partially communicating faults,however,these methods may not be accurate enough and may be limited in application,especially in complex situations.Numerical methods(i.e.finite difference or finite element)are also not computationally economical when a large number of grid blocks are simulated.In the current work,the Fast Marching Method(FMM)is applied to effectively mimic fluid flow in the heterogeneous areas,such as complex faults.It is shown that FMM can capture the effect of different fault configurations on the bottom hole pressure and is also able to capture different linear,radial and spherical flows.

An Incremental Model Transfer Method for Complex Process Fault Diagnosis

Fault diagnosis is an important measure to ensure the safety of production, and all kinds of fault diagnosis methods are of importance in actual production process. However, the complexity and uncertainty of production process often lead to the changes of data distribution and the emergence of new fault classes, and the number of the new fault classes is unpredictable. The reconstruction of the fault diagnosis model and the identification of new fault classes have become core issues under the circumstances. This paper presents a fault diagnosis method based on model transfer learning and the main contributions of the paper are as follows: 1) An incremental model transfer fault diagnosis method is proposed to reconstruct the new process diagnosis model. 2) Breaking the limit of existing method that the new process can only have one more class of faults than the old process, this method can identify M faults more in the new process with the thought of incremental learning. 3) The method offers a solution to a series of problems caused by the increase of fault classes. Experiments based on Tennessee-Eastman process and ore grinding classification process demonstrate the effectiveness and the feasibility of the method.

Fault diagnosis of time-delay complex dynamical networks using output signals

This paper proposes a novel approach for fault diagnosis of a time-delay complex dynamical network. Unlike the other methods, assuming that the dynamics of the network can be described by a linear stochastic model, or using the state variables of nodes in the network to design an adaptive observer, it only uses the output variable of the nodes to design an observer and an adaptive law of topology matrix in the observer of a complex network, leading to simple design of the observer and easy realisation of topology monitoring for the complex networks in real engineering. The proposed scheme can monitor any changes of the topology structure of a time-delay complex network. The effectiveness of this method is successfully demonstrated by virtue of a complex networks with Lorenz model.

Fault Tolerant Synchronization for a General Complex DynamicalNetwork with Random Delay

A fault tolerant synchronization strategy is proposed to synchronize a complex network with random time delays and sensor faults. Random time delays over the network transmission are described by using Markov chains. Based on the Lyapunov stability theory and stochastic analysis, several passive fault tolerant synchronization criteria are derived,which can be described in the form of linear matrix inequalities. Finally,a numerical simulation example is carried out and the results show the validity of the proposed fault tolerant synchronization controller.

DETECTION OF INCIPIENT LOCALIZED GEAR FAULTS IN GEARBOX BY COMPLEX CONTINUOUS WAVELET TRANSFORM

As far as the vibration signal processing is concerned, composition ofvibration signal resulting from incipient localized faults in gearbox is too weak to be detected bytraditional detecting technology available now. The method, which includes two steps: vibrationsignal from gearbox is first processed by synchronous average sampling technique and then it isanalyzed by complex continuous wavelet transform to diagnose gear fault, is introduced. Twodifferent kinds of faults in the gearbox, i.e. shaft eccentricity and initial crack in tooth fillet,are detected and distinguished from each other successfully.

Logging interpretation method for reservoirs with complex pore structure in Mesozoic-Cenozoic faulted basin around Daqing exploration area

In Mesozoic-Cenozoic faulted basin in the periphery of Daqing exploration area, the clastic reservoirs mainly consist of siltstone and gravel-bearing sandstone. The electrical conductivity of the reservoirs is complicated due to the complex pore structures, which cannot be accurately interpreted with commonly used model. In order to solve the problem, a three-water model has been applied in this study based on in-depth analysis of the conductive mechanism of rocks in the explored area, and favorable application results are achieved.

A Hierarchical Modeling and Fault Diagnosis Method for Complex Electronic Devices

Due to the shortcomings of the diagnosis systems for complex electronic devices such as failure models hard to build and low fault isolation resolution, a new hierarchical modeling and diagnosis method is proposed based on multisignal model and support vector machine （SVM）. Multisignal model is used to describe the failure propagation relationship in electronic device system, and the most probable failure printed circuit boards （PCBs） can be found by Bayes inference. The exact failure modes in the PCBs can be identified by SVM. The results show the proposed modeling and diagnosis method is effective and suitable for diagnosis for complex electronic devices.

Cellular automation model of faults and algorithmic complexity

In this paper, we use the cellular automation model to imitate earthquake process and draw some conclusionsof general applicability. First, it is confirmed that earthquake process has some ordering characters, and it isshown that both the existence and their mutual arrangement of faults could obviously influence the overallcharacters of earthquake process. Then the characters of each stage of model evolution are explained withself-organized critical state theory. Finally, earthquake sequences produced by the models are analysed interms pf algorithmic complexity and the result shows that AC-values of algorithmic complexity could be usedto study earthquake process and evolution.

First-principles study of stacking fault energies in Ni_3Al intermetallic alloys

The first-principles method based on the projector augmented wave method within the generalized gradient approximation was employed to calculate the superlattice intrinsic stacking fault（SISF） and complex stacking fault（CSF） energies of the binary Ni3Al alloys with different Al contents and the ternary Ni3Al intermetallic alloys with addition of alloying elements,such as Pd,Pt,Ti,Mo,Ta,W and Re.The results show that the energies of SISF and CSF increase significantly with increase of Al contents in Ni3Al.Addition of Pd and Pt occupying the Ni sublattices does not change the SISF and CSF energies of Ni3Al markedly in comparison with the Ni-23.75Al alloy.While addition of alloying elements,such as Ti,Mo,Ta,W and Re,occupying the Al sublattices dramatically increases the SISF and CSF energies of Ni3Al.The results suggest that the energies of SISF and CSF are dependent both on the Al contents and on the site occupancy of the ternary alloying element in Ni3Al intermetallic alloys.

Distribution pattern of deltaic sand bodies controlled by syn-depositional faults in a rift lacustrine basin

Take the lacustrine delta in the second member of Paleogene Shahejie Formation in block Wang43, Dongying depression, Bohai Bay Basin as an example, the deposition architectural characteristics of lacustrine deltaic sand bodies controlled by syn-depositional faults in complex fault blocks of rift basin are examined from the aspect of the tectonic-deposition response, using cores, well logs and three-dimensional seismic data. The small-scale syn-depositional faults in complex fault blocks are dense and different in dip, the activity along the strike of syn-depositional fault varies in different positions, and all these control the sedimentary process of deltaic sand bodies. Influenced by syn-depositional faults, the deltaic distributary channel is more likely to pass through the position with weak fault activity, and be deflected or limited at the position with strong fault activity. In downthrown side of a single syn-depositional fault or micro-graben areas, sand bodies increase in thickness and planar scale, and sand bodies of multiple stages are likely to stack over each other vertically. In micro-horst areas controlled by syn-depositional faults, the sand bodies decrease in abundance, and appear in intermittent superimposed pattern vertically. This study can provide new research ideas and theoretical basis for exploration and development research in complex fault blocks.

Geometrical textures of faults，evolution of physical field and instability characteristics

The spatial and temproal evolution of strain. fault displacement and acoustic emissions during deformation of fault systems with different geometrical textures are studied experimentally under biaxial compresison, and the characteristics of typical instability events are analysed. The results show that fault systems with different geometrical textures have different evolutional images of physical field during deformation. Based on the characteristics of physical field and the deformation mechanism, various types of instability - two types of stick-slip, fracturing type and mixed type instability can be recognized. Different types of instability differ clearly in their precursors, and the instability type is closely related with the geometrical texture and the deformation stage of the fault system. Therefore, it is very significant for earthquake prediction and precursor analysis to investigatethe geometrical textures of natural active faults.

NEW METHOD OF EXTRACTING WEAK FAILURE INFORMATION IN GEARBOX BY COMPLEX WAVELET DENOISING

Because the extract of the weak failure information is always the difficulty and focus of fault detection. Aiming for specific statistical properties of complex wavelet coefficients of gearbox vibration signals, a new signal-denoising method which uses local adaptive algorithm based on dual-tree complex wavelet transform （DT-CWT） is introduced to extract weak failure information in gear, especially to extract impulse components. By taking into account the non-Gaussian probability distribution and the statistical dependencies among wavelet coefficients of some signals, and by taking the advantage of near shift-invariance of DT-CWT, the higher signal-to-noise ratio （SNR） than common wavelet denoising methods can be obtained. Experiments of extracting periodic impulses in gearbox vibration signals indicate that the method can extract incipient fault feature and hidden information from heavy noise, and it has an excellent effect on identifying weak feature signals in gearbox vibration signals.

Metamorphic Core Complexes and Its Significance in the Continental Crustal Evolution

Metamorphic core complexes are a basic structural pattern related to extensional tectonics. Several characteristics of different scales of metamorphic core complexes in the Fangshan and Yunmengshan (Beijing) , Zhongtiaoshan (Shanxi) , and Dengfong (Henan) are examined. A three-layer model for metam orphic core complexes is suggested . The conclusion is that metam orphic core complexes are the result of multiphase intracontinental crustal extensions and are an important tectonic pattern. which exposes the basement metam orphic rocks to the ground surface in the intracontinental cover .

Multistage Extension and Age Dating of the Xiaoqinling Metamorphic Core Complex,Central China

Abstract There are two extensional systems in the Xiaoqinling metamorphic core complex (XMCC). One is the detachment fault system developed along the peripheries of the XMCC, which extended in an ESE-WNW direction and whose upper plate moved towards the WNW. The other extensional system includes the retrograde shear zones and normal faults developed within the XMCC, which represent the collapse of the XMCC. Ar-Ar and K-Ar dating shows that the extension of the detachment fault system continued from 135 to 123 Ma, i.e. in the late stage of its evolution at about 127 Ma. The collapse represented by the extensional system within the XMCC was operative during 120–106 Ma, and its main activity occurred about 116 Ma ago. These suggest that the XMCC experienced two extensional stages in its evolution, i.e., the syn-orogenic regional extension and post-orogenic collapse extension.

A new method to calculate near-field radiation excited by heterogeneous fault rupture

This paper derives from the representation theory the formula for calculating the radiation excited by heterogeneous fault rupture based on box-like discretization scheme. Preliminary validation indicates that our algorithm has very high computation precision and efficiency; therefore, it is a very practical tool to investigate strong ground motion problems. Additionally, the equations given in this study can also be used to invert the fault rupture process.