2011 Vol. 39 No. 6
2011, 39(6): 1-5.
DOI: 10.3969/j.issn.1001-1986.2011.06.001
Abstract：
Based on the study of the stratigraphy sequence of the Bayanhua Formation of low Cretaceous in Wunite coafield, two sequence boundaries SB1 and SB2 were distinguished, three third sequences including SMC1, SMC2 and SMC3 were divided, and the stratigraphy framework of the Bayanhua Formation was established.The facies analysis shows that the strata were developed from lacustrine facies, delta facies and fluvial facies deposition.And lake offshore facies and river delta facies were the predominant paleoenvironment for coal formation.Finally, according to the core data, thickness of the coal layer, the proportion of sand and mud in the strata and the distribution of the stratigraphy sequence, the lithofacies paleographic map was made, which will provide a helpful guidance to the exploration and development of the coal around the area.
Based on the study of the stratigraphy sequence of the Bayanhua Formation of low Cretaceous in Wunite coafield, two sequence boundaries SB1 and SB2 were distinguished, three third sequences including SMC1, SMC2 and SMC3 were divided, and the stratigraphy framework of the Bayanhua Formation was established.The facies analysis shows that the strata were developed from lacustrine facies, delta facies and fluvial facies deposition.And lake offshore facies and river delta facies were the predominant paleoenvironment for coal formation.Finally, according to the core data, thickness of the coal layer, the proportion of sand and mud in the strata and the distribution of the stratigraphy sequence, the lithofacies paleographic map was made, which will provide a helpful guidance to the exploration and development of the coal around the area.
2011, 39(6): 6-10,15.
DOI: 10.3969/j.issn.1001-1986.2011.06.002
Abstract：
The contents of the major and trace elements in 3 samples of the claystone with different types and textures, from the coal measures of the Taiyuan and Shanxi Formations of Permo-Carboniferous of Xiaoyu coal mine of Datong, Shanxi province, are detected by the methods of chemical analysis and INAA respectively.By the contrast analysis of the elements with geochemical tracer and their ratio, three samples, on geochemistry as a whole, are not of the typical characteristics of sedimentogenic mudstone, and could be formed in situ from the alteration of acidic or alkali-acidic ash (fallout or water-carried) under the conditions of the shallower water and weak oxydation on the surface.The alteration of the claystone is stronger on the whole, and it causes much loss of the unstable elements, even some of more stable elements, such as ferromolybdenum and manganese.The environments, medium conditions and original matter and its size at the ash alteration, as well as the clay minerals of the clay rocks are the major reason of the differences on the types and element contents of the claystones.
The contents of the major and trace elements in 3 samples of the claystone with different types and textures, from the coal measures of the Taiyuan and Shanxi Formations of Permo-Carboniferous of Xiaoyu coal mine of Datong, Shanxi province, are detected by the methods of chemical analysis and INAA respectively.By the contrast analysis of the elements with geochemical tracer and their ratio, three samples, on geochemistry as a whole, are not of the typical characteristics of sedimentogenic mudstone, and could be formed in situ from the alteration of acidic or alkali-acidic ash (fallout or water-carried) under the conditions of the shallower water and weak oxydation on the surface.The alteration of the claystone is stronger on the whole, and it causes much loss of the unstable elements, even some of more stable elements, such as ferromolybdenum and manganese.The environments, medium conditions and original matter and its size at the ash alteration, as well as the clay minerals of the clay rocks are the major reason of the differences on the types and element contents of the claystones.
2011, 39(6): 11-15.
DOI: 10.3969/j.issn.1001-1986.2011.06.003
Abstract：
Joint propagation changes the physical and mechanical properties of coal due to in-site stress, then the redistribution of coal seam stress and deformation is caused, so the calculation method of coal element joints propagation is given, and relationship between joint propagation and stress is analyzed.Application of wavelet neural network and gradual loading algorithm, a methodology of inversion analysis of coal seam stress field is presented, and the distribution regularity of in-site field is studied for Jincheng block in Qinshui basin using combined inversion algorithm.The results show that the block maximum principal stress increases from northwest to southeast, and it ranges from 8 to 13Mpa; the minimum principal stress is located in Southern Jincheng, and the value is about 5-9MPa.Comparison of combined inversion algorithm results with measured values of the key points indicates that the principal stress relative error is only 3%, and azimuth error is less than 1.3°.So combined inversion analysis has higher calculation accuracy and can satisfy the engineering demand, also it has a series of advantages, such as simple model, fast calculating speed, and so on.
Joint propagation changes the physical and mechanical properties of coal due to in-site stress, then the redistribution of coal seam stress and deformation is caused, so the calculation method of coal element joints propagation is given, and relationship between joint propagation and stress is analyzed.Application of wavelet neural network and gradual loading algorithm, a methodology of inversion analysis of coal seam stress field is presented, and the distribution regularity of in-site field is studied for Jincheng block in Qinshui basin using combined inversion algorithm.The results show that the block maximum principal stress increases from northwest to southeast, and it ranges from 8 to 13Mpa; the minimum principal stress is located in Southern Jincheng, and the value is about 5-9MPa.Comparison of combined inversion algorithm results with measured values of the key points indicates that the principal stress relative error is only 3%, and azimuth error is less than 1.3°.So combined inversion analysis has higher calculation accuracy and can satisfy the engineering demand, also it has a series of advantages, such as simple model, fast calculating speed, and so on.
2011, 39(6): 16-19,23.
DOI: 10.3969/j.issn.1001-1986.2011.06.004
Abstract：
Spontaneous combustion tendency is one of the major influence factors for coal spontaneous combustion.Based on the analysis of appraisal methods of coal spontaneous combustion tendency, the disadvantages of actual appraisal method of coal spontaneous combustion tendency in China are pointed out.According to the coal- oxygen complex theory of coal spontaneous combustion mechanism, taking oxygen absorptivity, exothermic intensity and activation energy during coal combustion process as influencing factors for appraising coal spontaneous combustion tendency, fuzzy comprehensive evaluation method was developed.On this condition, five coal samples parameters under the same conditions were tested by thermogravimetry analysis method, and fuzzy comprehensive evaluation model was established.Then synthetic indexes of spontaneous combustion tendency for five coal samples were obtained by fuzzy calculation.Through test, this method is of better practicability, and the evaluation results are of complete consistency with the tendency of actual coal spontaneous combustion.
Spontaneous combustion tendency is one of the major influence factors for coal spontaneous combustion.Based on the analysis of appraisal methods of coal spontaneous combustion tendency, the disadvantages of actual appraisal method of coal spontaneous combustion tendency in China are pointed out.According to the coal- oxygen complex theory of coal spontaneous combustion mechanism, taking oxygen absorptivity, exothermic intensity and activation energy during coal combustion process as influencing factors for appraising coal spontaneous combustion tendency, fuzzy comprehensive evaluation method was developed.On this condition, five coal samples parameters under the same conditions were tested by thermogravimetry analysis method, and fuzzy comprehensive evaluation model was established.Then synthetic indexes of spontaneous combustion tendency for five coal samples were obtained by fuzzy calculation.Through test, this method is of better practicability, and the evaluation results are of complete consistency with the tendency of actual coal spontaneous combustion.
2011, 39(6): 20-23.
DOI: 10.3969/j.issn.1001-1986.2011.06.005
Abstract：
The exploitation of CBM is different from conventional gas.The water in coal needs to be drained in CBM wells before the gas come out, so well grid pattern is usually used in CBM exploitation in order to get better effect of water drainage and depressurization, the arrangement of well pattern directly affects the success of CBM development and the level of ultimate recovery.This paper presents the optimization design principle of CBM well pattern and factors such as well interference, anisotropy, well spacing, well density and direction, then conducts optimization design of CBM well pattern aiming at an area in Ordos basin by numerical simulation software, thus providing reasonable basis for development program design of the area.
The exploitation of CBM is different from conventional gas.The water in coal needs to be drained in CBM wells before the gas come out, so well grid pattern is usually used in CBM exploitation in order to get better effect of water drainage and depressurization, the arrangement of well pattern directly affects the success of CBM development and the level of ultimate recovery.This paper presents the optimization design principle of CBM well pattern and factors such as well interference, anisotropy, well spacing, well density and direction, then conducts optimization design of CBM well pattern aiming at an area in Ordos basin by numerical simulation software, thus providing reasonable basis for development program design of the area.
2011, 39(6): 24-27.
DOI: 10.3969/j.issn.1001-1986.2011.06.006
Abstract：
The fluid flowing state of coalbed methane is a phase parameter reflecting difficult or easy level for CBM flowing in medium.Based on comprehending the previous experience, and by interpreting and deducing the fluid flowing equation for coalbed methane, the limits of fluid flowing states are divided and the distribution characteristics of fluid flowing state of CBM in reservoir are related with permeability and migration distance is also obtained.It can provide greatly theory supports in drafting reasonable development plans for CBM and has great practical values.
The fluid flowing state of coalbed methane is a phase parameter reflecting difficult or easy level for CBM flowing in medium.Based on comprehending the previous experience, and by interpreting and deducing the fluid flowing equation for coalbed methane, the limits of fluid flowing states are divided and the distribution characteristics of fluid flowing state of CBM in reservoir are related with permeability and migration distance is also obtained.It can provide greatly theory supports in drafting reasonable development plans for CBM and has great practical values.
2011, 39(6): 28-31,35.
DOI: 10.3969/j.issn.1001-1986.2011.06.007
Abstract：
To make the exploitation of Liulin CBM reasonable and efficient, the flow velocity sensitivity, water sensitivity, alkaline sensitivity and acid sensitivity of Liulin coal samples were tested and evaluated.The results show that Shanxi coal's velocity sensitivity extent is from medium weak to medium strong and the critical flow velocity is low; The damage caused by water sensitivity is from non to medium strong; The damage caused by alkaline sensitivity is from medium weak to strong and the value of critical pH is 7.In addition, the damage caused by alkaline sensitivity of coal positively relates with the number of adsorbed hydroxide; The hydrochloric acid sensitivity index is -2.546 to 0.004 5, and no acid sensitivity.To sum up, the fluid velocity of fall should be controlled below 2 m/d to achieve a smooth pressure reduction at the beginning of CBM exploitation; 1%～2% KCl is used as clay stabilizer; the pH of operation fluid should be kept below 7.
To make the exploitation of Liulin CBM reasonable and efficient, the flow velocity sensitivity, water sensitivity, alkaline sensitivity and acid sensitivity of Liulin coal samples were tested and evaluated.The results show that Shanxi coal's velocity sensitivity extent is from medium weak to medium strong and the critical flow velocity is low; The damage caused by water sensitivity is from non to medium strong; The damage caused by alkaline sensitivity is from medium weak to strong and the value of critical pH is 7.In addition, the damage caused by alkaline sensitivity of coal positively relates with the number of adsorbed hydroxide; The hydrochloric acid sensitivity index is -2.546 to 0.004 5, and no acid sensitivity.To sum up, the fluid velocity of fall should be controlled below 2 m/d to achieve a smooth pressure reduction at the beginning of CBM exploitation; 1%～2% KCl is used as clay stabilizer; the pH of operation fluid should be kept below 7.
2011, 39(6): 32-35.
DOI: 10.3969/j.issn.1001-1986.2011.06.008
Abstract：
Decades of underground mining around Jincheng city results in a large quantity of goaf.By virtue of remote sensing geology interpretation as well as investigation, and research on technical materials of multi-temporal satellite images, aerophotos, digital elevation models, the paper gives a fairly comprehensive grasp of goaf around Jincheng city.28sinks and 23crevices are determined in the goaf.According to various factors, such as goaf's age, roof lithology, the number of the exploited layers, and the status of ground sinks, the goaf is divided into three types: extremely instable area, instable area, and comparatively instable area.5extremely instable areas, 4instable areas and 13comparatively instable areas are determined.
Decades of underground mining around Jincheng city results in a large quantity of goaf.By virtue of remote sensing geology interpretation as well as investigation, and research on technical materials of multi-temporal satellite images, aerophotos, digital elevation models, the paper gives a fairly comprehensive grasp of goaf around Jincheng city.28sinks and 23crevices are determined in the goaf.According to various factors, such as goaf's age, roof lithology, the number of the exploited layers, and the status of ground sinks, the goaf is divided into three types: extremely instable area, instable area, and comparatively instable area.5extremely instable areas, 4instable areas and 13comparatively instable areas are determined.
2011, 39(6): 36-40.
DOI: 10.3969/j.issn.1001-1986.2011.06.009
Abstract：
Prediction of water outburst in seam floor of mines is a complex theoretic and technical problem, which has characters of fuzziness, grey and incompatibility.By building the factor index system and getting nine main factors through the grey correlation, the contribution weights are ascertained by the entropy adjustment.According to the grey matter-element analysis theory, it builds the linear grey matter-element and optimal grey matter-element model respectively, the discrimination system of combined grey matter-element for water outburst in seam floor of deep mines is exploited by VB 6.0.The two module in parallel operation and mutual verification can much raise the result precision, it is basically capable of forecasting deep seam mining faces which are all threatened by the Ordovician limestone water.The answer of simulation analysis applying this system to the realistic water-bursting cases is in good accordance with the truth condition.The system will be of some values for controlling and preventing deep seam water-bursting from coal floor in complex state.
Prediction of water outburst in seam floor of mines is a complex theoretic and technical problem, which has characters of fuzziness, grey and incompatibility.By building the factor index system and getting nine main factors through the grey correlation, the contribution weights are ascertained by the entropy adjustment.According to the grey matter-element analysis theory, it builds the linear grey matter-element and optimal grey matter-element model respectively, the discrimination system of combined grey matter-element for water outburst in seam floor of deep mines is exploited by VB 6.0.The two module in parallel operation and mutual verification can much raise the result precision, it is basically capable of forecasting deep seam mining faces which are all threatened by the Ordovician limestone water.The answer of simulation analysis applying this system to the realistic water-bursting cases is in good accordance with the truth condition.The system will be of some values for controlling and preventing deep seam water-bursting from coal floor in complex state.
2011, 39(6): 41-44.
DOI: 10.3969/j.issn.1001-1986.2011.06.010
Abstract：
A practical engineering of the long-short-pile composite foundation is presented.By means of finite element analytical method, the stress distribution and displacement of four foundations reinforced by long-short-pile composite foundation, whole long piles, whole short piles and raft foundation under the same geological conditions have been compared and analyzed.The research results show that under the same loading condition, the characteristics of foundation reinforced by whole short piles are approximate to those of natural foundation while the characteristics of foundation reinforced by long-short-pile composite foundation are similar with those of foundation reinforced by whole long piles.Compared with foundation reinforced by whole short piles and raft foundation, the long-short-pile composite foundation can reduce the whole settlement and the settlement difference of foundation effectively, and it makes foundation more reasonable.Furthermore, long-short-pile composite foundation can achieve great economical benefit compared with whole long piles, therefore, it will be of immense foreground for engineering practice.
A practical engineering of the long-short-pile composite foundation is presented.By means of finite element analytical method, the stress distribution and displacement of four foundations reinforced by long-short-pile composite foundation, whole long piles, whole short piles and raft foundation under the same geological conditions have been compared and analyzed.The research results show that under the same loading condition, the characteristics of foundation reinforced by whole short piles are approximate to those of natural foundation while the characteristics of foundation reinforced by long-short-pile composite foundation are similar with those of foundation reinforced by whole long piles.Compared with foundation reinforced by whole short piles and raft foundation, the long-short-pile composite foundation can reduce the whole settlement and the settlement difference of foundation effectively, and it makes foundation more reasonable.Furthermore, long-short-pile composite foundation can achieve great economical benefit compared with whole long piles, therefore, it will be of immense foreground for engineering practice.
2011, 39(6): 45-47,53.
DOI: 10.3969/j.issn.1001-1986.2011.06.011
Abstract：
Based on anchor bolt (cable) mechanism and analysis of the action of anchor bolt (cable) on rocks mechanical effects, the paper studied the force and deformation characteristics of anchor bolt (cable), explored the feasibility of the use of the disc tray combination for yield supporting on bolting supporting.Under high stress, large deformation and impact load, the bolt capacity is not affected in the premise of ensuring that supporting body had certain deformation, through release of some stress, bolt breaking was reduced and avoided, effectively improving bolt support effect.
Based on anchor bolt (cable) mechanism and analysis of the action of anchor bolt (cable) on rocks mechanical effects, the paper studied the force and deformation characteristics of anchor bolt (cable), explored the feasibility of the use of the disc tray combination for yield supporting on bolting supporting.Under high stress, large deformation and impact load, the bolt capacity is not affected in the premise of ensuring that supporting body had certain deformation, through release of some stress, bolt breaking was reduced and avoided, effectively improving bolt support effect.
2011, 39(6): 48-53.
DOI: 10.3969/j.issn.1001-1986.2011.06.012
Abstract：
Whenchuan earthquake triggered many geo-hazards in Chenjiaba in Beichuan area, and Sunjiayuan rockslide was one of the biggest ones In the rockslide back-wall a special russet rock shell was revealed, which had strength higher than that of the underlying bed rock.A new definition named sliding-surface breccia was brought according to the characteristics and mineral identification of this special rock shell.By analyzing the mechanism of fast rock granular cementation, it is proved that under the severe earthquake and certain specific geological and topographical conditions, the temperature in the sliding zone can rise to meet the required temperature under which rock particles in the sliding zone can be conglomerated by ferruginous cementation.In addition, this temperature is far lower than the mineral melting temperature of rocks.
Whenchuan earthquake triggered many geo-hazards in Chenjiaba in Beichuan area, and Sunjiayuan rockslide was one of the biggest ones In the rockslide back-wall a special russet rock shell was revealed, which had strength higher than that of the underlying bed rock.A new definition named sliding-surface breccia was brought according to the characteristics and mineral identification of this special rock shell.By analyzing the mechanism of fast rock granular cementation, it is proved that under the severe earthquake and certain specific geological and topographical conditions, the temperature in the sliding zone can rise to meet the required temperature under which rock particles in the sliding zone can be conglomerated by ferruginous cementation.In addition, this temperature is far lower than the mineral melting temperature of rocks.
2011, 39(6): 54-57.
DOI: 10.3969/j.issn.1001-1986.2011.06.013
Abstract：
To reveal the ground settlement regularities of thawing of artificial freezing soil, based on a horizontal freezing engineering project of shield tunneling for construction of a subway, the ground displacement induced by thaw-settlement in artificial freezing soil was studied with 3D numerical simulation analysis.The results showed that settlement of ground surface can be divided into 4 stages: slow settlement, rapid subsidence, stationary settlement and consolidation settlement.Above the tunnel axis, with the increase of distance from the sealed door, ground surface settlement was increased first and then decreased.Land subsidence in the cross section was similar to normal distribution curve.With the increase of horizontal distance from the axis, land subsidence was decreased and there is an obvious inflection point of the curve.With the increase of distance from the tunnel axis, the horizontal distance of land increased first and then decreased.The maximum horizontal displacement corresponds to the position of inflection point.The ground settlement above the tunnel caused by the thaw-settlement increased with the increase of depth.The ground settlement was smaller when the distance was farther away from the freezing zone.
To reveal the ground settlement regularities of thawing of artificial freezing soil, based on a horizontal freezing engineering project of shield tunneling for construction of a subway, the ground displacement induced by thaw-settlement in artificial freezing soil was studied with 3D numerical simulation analysis.The results showed that settlement of ground surface can be divided into 4 stages: slow settlement, rapid subsidence, stationary settlement and consolidation settlement.Above the tunnel axis, with the increase of distance from the sealed door, ground surface settlement was increased first and then decreased.Land subsidence in the cross section was similar to normal distribution curve.With the increase of horizontal distance from the axis, land subsidence was decreased and there is an obvious inflection point of the curve.With the increase of distance from the tunnel axis, the horizontal distance of land increased first and then decreased.The maximum horizontal displacement corresponds to the position of inflection point.The ground settlement above the tunnel caused by the thaw-settlement increased with the increase of depth.The ground settlement was smaller when the distance was farther away from the freezing zone.
2011, 39(6): 58-62.
DOI: 10.3969/j.issn.1001-1986.2011.06.014
Abstract：
The paper, combined with engineering practices in loess area of west Shanxi, through field investigation and measurement, laboratory experiments, numeric calculation, aimed at different slope height (8m, 16m, 24m, 32m, 45m), using analogy, anti-algorithm, literature and numeric calculation to carry out analysis and study, derived the optimal rate of loess slope with different height.The results have been used in construction projects of the area.It can save project investment, protect the geological environments in construction area, also provide reference for similar construction projects in other areas.
The paper, combined with engineering practices in loess area of west Shanxi, through field investigation and measurement, laboratory experiments, numeric calculation, aimed at different slope height (8m, 16m, 24m, 32m, 45m), using analogy, anti-algorithm, literature and numeric calculation to carry out analysis and study, derived the optimal rate of loess slope with different height.The results have been used in construction projects of the area.It can save project investment, protect the geological environments in construction area, also provide reference for similar construction projects in other areas.
2011, 39(6): 63-66,71.
DOI: 10.3969/j.issn.1001-1986.2011.06.015
Abstract：
The generalized S-transform with variable-factor is a new time-frequency decomposition method, which is more practical than the traditional S-transform and the generalized S-transform developed by Mansinha.When the scale of the gaussian window function varies with the frequency, the existence of the variable-factor makes this variation have goals, rather than simply narrowing as frequency increasing.This transform can improve the frequency resolution or the time resolution of the local band with purpose, especially the low and high frequency band.A time-frequency filtering method based on the transform is developed.Through filtration of synthetic seismic records, the result proves its effectiveness.
The generalized S-transform with variable-factor is a new time-frequency decomposition method, which is more practical than the traditional S-transform and the generalized S-transform developed by Mansinha.When the scale of the gaussian window function varies with the frequency, the existence of the variable-factor makes this variation have goals, rather than simply narrowing as frequency increasing.This transform can improve the frequency resolution or the time resolution of the local band with purpose, especially the low and high frequency band.A time-frequency filtering method based on the transform is developed.Through filtration of synthetic seismic records, the result proves its effectiveness.
2011, 39(6): 67-71.
DOI: 10.3969/j.issn.1001-1986.2011.06.016
Abstract：
Multi-scale wavelet analysis theory is applied to study water inflow in mine face, spontaneous potential and water level of directly water-charged aquifer.It is found that there exists close relationship among these three types of data by wavelet decomposition and reconstruction.The regularity in the 2nd signal of the low-frequency reconstructing is that spontaneous potential rises due to water level fall, causing increased water inflow when the water level rebounds and spontaneous potential reduces as well as the corresponding water inflow reduces.The regularity in the 2nd reconstructed signal of low frequency is that high water level and low spontaneous potential are corresponding with small water inflow, low water level and high spontaneous potential are corresponding with large water inflow.
Multi-scale wavelet analysis theory is applied to study water inflow in mine face, spontaneous potential and water level of directly water-charged aquifer.It is found that there exists close relationship among these three types of data by wavelet decomposition and reconstruction.The regularity in the 2nd signal of the low-frequency reconstructing is that spontaneous potential rises due to water level fall, causing increased water inflow when the water level rebounds and spontaneous potential reduces as well as the corresponding water inflow reduces.The regularity in the 2nd reconstructed signal of low frequency is that high water level and low spontaneous potential are corresponding with small water inflow, low water level and high spontaneous potential are corresponding with large water inflow.
2011, 39(6): 72-75.
DOI: 10.3969/j.issn.1001-1986.2011.06.017
Abstract：
Using SD-I acoustic detector, we examine the No.15 coal seam in Shouyang block of Shanxi Province.The uniaxial compressive strength test is carried out on the MTS815 Servo-controlled Rock Mechanical Test System.We discuss the relationship between the velocity of P-wave and the coal intensity, and that between the dynamic and static elastic parameters.Test results indicate that: uniaxial compressive strength of coal and the P-wave velocity show a good exponential relationship, uniaxial compressive strength increase with the P-wave velocity; the dynamic and static elastic modulus show a good linear relationship, and the dynamic elastic modulus is usually greater than the static elastic modulus; the static and dynamic Poisson's ratio is positively correlated.
Using SD-I acoustic detector, we examine the No.15 coal seam in Shouyang block of Shanxi Province.The uniaxial compressive strength test is carried out on the MTS815 Servo-controlled Rock Mechanical Test System.We discuss the relationship between the velocity of P-wave and the coal intensity, and that between the dynamic and static elastic parameters.Test results indicate that: uniaxial compressive strength of coal and the P-wave velocity show a good exponential relationship, uniaxial compressive strength increase with the P-wave velocity; the dynamic and static elastic modulus show a good linear relationship, and the dynamic elastic modulus is usually greater than the static elastic modulus; the static and dynamic Poisson's ratio is positively correlated.
2011, 39(6): 76-80.
DOI: 10.3969/j.issn.1001-1986.2011.06.018
Abstract：
Drilling needs to master the drilling process, and identify the stratum in real time, which is a key factor in improving the drilling efficiency.According to the bit excited in the layers with different characteristics of the vibration signal, the paper put forward correlation function-wavelet transform analysis.Cross-correlation will be used to extract the delay information of pre-sentence level or target level, and time-frequency components are extracted by using multi-resolution analysis of wavelet to determine the stratum in real time.Both simulations and experimental research prove that cross-correlation-wavelet transform can accurately characterize the time delay and time-frequency information, and forecast bit drilling situation and information, has high accuracy of real-time and some practical value in improving the efficiency.
Drilling needs to master the drilling process, and identify the stratum in real time, which is a key factor in improving the drilling efficiency.According to the bit excited in the layers with different characteristics of the vibration signal, the paper put forward correlation function-wavelet transform analysis.Cross-correlation will be used to extract the delay information of pre-sentence level or target level, and time-frequency components are extracted by using multi-resolution analysis of wavelet to determine the stratum in real time.Both simulations and experimental research prove that cross-correlation-wavelet transform can accurately characterize the time delay and time-frequency information, and forecast bit drilling situation and information, has high accuracy of real-time and some practical value in improving the efficiency.
