Accuracy of time-depth conversion in data processing of transient electromagnetic prospecting always affects the accu- rate positioning of water bodies in coal mines. In order to improve the accuracy of time-depth con...Accuracy of time-depth conversion in data processing of transient electromagnetic prospecting always affects the accu- rate positioning of water bodies in coal mines. In order to improve the accuracy of time-depth conversion, we established a mathe- matical model of time-depth conversion for a transient electromagnetic method based on the theory of "double smoke ring effect" of full space transient electromagnetic field transmission. Using a 3-layer as well as a 4-layer geo-electric model for roadway floors, we performed the time-depth conversion of theoretical curves of apparent resistance varying over time. In these curves, the depth corresponding to extreme value points is nearly the same as the depth of a geo-electric model. The position of water body deter- mined by our time-depth conversion method agrees well with the result of borehole drilling, indicating that the established time-depth conversion model can clearly improve the accuracy of spatial positioning of water bodies in coal mines.展开更多
There are rich natural gas resources in the northwestern South China Sea deepwater areas, with poor degree of exploration. Because of the unique tectonic, sedimentary background of the region, velocity model building ...There are rich natural gas resources in the northwestern South China Sea deepwater areas, with poor degree of exploration. Because of the unique tectonic, sedimentary background of the region, velocity model building and time-depth conversion have been an important and difficult problem for a long time. Recent researches in this direction have revealed three major problems for deepwater areas, i.e., the way to determine error correction for drilling velocity, the optimization of velocity modeling, and the understanding and analysis of velocity variations in the slope areas. The present contribution proposes technical solutions to the problems：（1） velocity correction version can be established by analyzing the geology, reservoir, water depths and velocity spectrum characteristics;（2） a unified method can be adopted to analyze the velocity variation patterns in drilled pale structural positions;and （3） across-layer velocity is analyzed to establish the velocity model individually for each of the layers. Such a solution is applicable, as shown in an example from the northwestern South China Sea deepwater areas, in which an improved prediction precision is obtained.展开更多
叠前偏移技术在地震数据处理中发挥着非常重要的作用。然而,利用偏移速度分析方法处理复杂地质构造时,往往难以精准重建速度模型,导致共成像点道集的同相轴发生弯曲,影响构造的成像精度。基于动态时间规整算法的地震数据叠加方法通过匹...叠前偏移技术在地震数据处理中发挥着非常重要的作用。然而,利用偏移速度分析方法处理复杂地质构造时,往往难以精准重建速度模型,导致共成像点道集的同相轴发生弯曲,影响构造的成像精度。基于动态时间规整算法的地震数据叠加方法通过匹配参考地震道与其他地震道的相似性来校正同相轴的一致性,但当各地震道之间的幅值差异较大,或者地震数据信噪比较低时,该方法易出现错误匹配的情况,进而导致波形发生畸变,因而影响了其在道集校正中的应用效果。针对上述问题,提出了一种基于迭代光滑动态时间规整算法(iterative smooth dynamic time warping,ISDTW)的共成像点道集叠加方法,该方法引入平滑约束和迭代策略对规整路径进行优化,提高了道集的校正精度和同相轴的一致性。特别是在复杂地质条件下,ISDTW算法取得了较好的成像效果。合成数据和实际数据的测试结果验证了ISDTW算法在减少局部匹配误差、提升地震成像质量方面的显著优势。展开更多
It is known that rock anisotropy can significantly influence the phase and energy velocities of an elastic wave,as well as its reflection/transmission(R/T)coefficients.As a result,it can distort the velocity analysis ...It is known that rock anisotropy can significantly influence the phase and energy velocities of an elastic wave,as well as its reflection/transmission(R/T)coefficients.As a result,it can distort the velocity analysis of seismic-reflection data.In this work we present a velocity analysis for seismic-reflection data based on the available anisotropic rock parameters.We analyzed the created errors on time-depth relation of the seismic-reflection data in neglecting rock anisotropy and/or neglecting the difference between energy velocity and phase velocity,including the case of wide-angle reflection.The calculated results show that the effect of rock anisotropy on time-depth relation of seismic-reflection data is dependent not only on the values of anisotropic parameters,but also on the space arrangement of both source and receiver-array.For all studied cases(weak,moderate or strong anisotropy),we found that the effect of rock anisotropy on time-depth relation could not be neglected.Nevertheless,for the case of weak anisotropy,the energy velocity may be replaceable by the phase velocity to obtain a very good approximation on time-depth relation.Consequently,the seismic-reflection data processing algorithm for numerical computations can be simplified.展开更多
As the well drilling depth has broken through the 10,000 m in China,accurate measurements of downhole engineering parameters,such as annulus temperature and pressure for the whole wellbore,are significant in controlli...As the well drilling depth has broken through the 10,000 m in China,accurate measurements of downhole engineering parameters,such as annulus temperature and pressure for the whole wellbore,are significant in controlling potential downhole complexities.In this present work,a new micro-measurer is developed by integrating measurements of downhole temperature,pressure,magnetic field strength,and its own dynamic signals.The micro-measurer can flow with drilling fluid from the drillstring to the bottomhole and then float up back to the ground via the wellbore annulus.Compared with other downhole measurement tools that are fixedly connected to the drill string,its“measure-and-move-on”approach reduces the residence time in the high-temperature and high-pressure zone at the bottomhole;moreover,both the pressure and temperature at different well depth can be measured,thereby the temperature and pressure profiles of the whole wellbore can be constructed.In addition,the bluetooth low energy(BLE)technique is applied to offer the micro-measurer with the capability of wireless information transmission;while hydrodynamic optimization of the micro-measurer is carried out to design the structure of the micro-measurer,which can promote its recovery rate from downhole.In addition,an intelligent joint for releasing micro-measurers from the wellbore annulus is also proposed,aiming to overcome the limitation imposed by the nozzle on the size of the micro-measurer.Both the indoor experiments and the field tests have verified the feasibility of the newly designed micro-measurer,which is a key step for establishing a complete downhole internet of things(IoT)system to serve the intelligent drilling in the future.展开更多
基金Project 2007CB209400 supported by the National Basic Research Program of China
文摘Accuracy of time-depth conversion in data processing of transient electromagnetic prospecting always affects the accu- rate positioning of water bodies in coal mines. In order to improve the accuracy of time-depth conversion, we established a mathe- matical model of time-depth conversion for a transient electromagnetic method based on the theory of "double smoke ring effect" of full space transient electromagnetic field transmission. Using a 3-layer as well as a 4-layer geo-electric model for roadway floors, we performed the time-depth conversion of theoretical curves of apparent resistance varying over time. In these curves, the depth corresponding to extreme value points is nearly the same as the depth of a geo-electric model. The position of water body deter- mined by our time-depth conversion method agrees well with the result of borehole drilling, indicating that the established time-depth conversion model can clearly improve the accuracy of spatial positioning of water bodies in coal mines.
基金The National Twelfth Five Major Projects Subject--the deepwater area of northern South China Sea,rich hydrocarbon generation potential sag evaluation under contract No.2011ZX05025-002
文摘There are rich natural gas resources in the northwestern South China Sea deepwater areas, with poor degree of exploration. Because of the unique tectonic, sedimentary background of the region, velocity model building and time-depth conversion have been an important and difficult problem for a long time. Recent researches in this direction have revealed three major problems for deepwater areas, i.e., the way to determine error correction for drilling velocity, the optimization of velocity modeling, and the understanding and analysis of velocity variations in the slope areas. The present contribution proposes technical solutions to the problems：（1） velocity correction version can be established by analyzing the geology, reservoir, water depths and velocity spectrum characteristics;（2） a unified method can be adopted to analyze the velocity variation patterns in drilled pale structural positions;and （3） across-layer velocity is analyzed to establish the velocity model individually for each of the layers. Such a solution is applicable, as shown in an example from the northwestern South China Sea deepwater areas, in which an improved prediction precision is obtained.
文摘叠前偏移技术在地震数据处理中发挥着非常重要的作用。然而,利用偏移速度分析方法处理复杂地质构造时,往往难以精准重建速度模型,导致共成像点道集的同相轴发生弯曲,影响构造的成像精度。基于动态时间规整算法的地震数据叠加方法通过匹配参考地震道与其他地震道的相似性来校正同相轴的一致性,但当各地震道之间的幅值差异较大,或者地震数据信噪比较低时,该方法易出现错误匹配的情况,进而导致波形发生畸变,因而影响了其在道集校正中的应用效果。针对上述问题,提出了一种基于迭代光滑动态时间规整算法(iterative smooth dynamic time warping,ISDTW)的共成像点道集叠加方法,该方法引入平滑约束和迭代策略对规整路径进行优化,提高了道集的校正精度和同相轴的一致性。特别是在复杂地质条件下,ISDTW算法取得了较好的成像效果。合成数据和实际数据的测试结果验证了ISDTW算法在减少局部匹配误差、提升地震成像质量方面的显著优势。
基金supported by the National Natural Science Foundation of China(40974078)the US Department of Energy(DE-FC2608NT0 005643)+1 种基金the Natural Science Foundation of Shaanxi Province,China (2007D15)North Dakota Industrial Commission with five industrial companies:Encore Acquisition,Hess,Marathon Oil,St.Mary Land & Exploration,and Whiting Petroleum(NDIC-G015-031)
文摘It is known that rock anisotropy can significantly influence the phase and energy velocities of an elastic wave,as well as its reflection/transmission(R/T)coefficients.As a result,it can distort the velocity analysis of seismic-reflection data.In this work we present a velocity analysis for seismic-reflection data based on the available anisotropic rock parameters.We analyzed the created errors on time-depth relation of the seismic-reflection data in neglecting rock anisotropy and/or neglecting the difference between energy velocity and phase velocity,including the case of wide-angle reflection.The calculated results show that the effect of rock anisotropy on time-depth relation of seismic-reflection data is dependent not only on the values of anisotropic parameters,but also on the space arrangement of both source and receiver-array.For all studied cases(weak,moderate or strong anisotropy),we found that the effect of rock anisotropy on time-depth relation could not be neglected.Nevertheless,for the case of weak anisotropy,the energy velocity may be replaceable by the phase velocity to obtain a very good approximation on time-depth relation.Consequently,the seismic-reflection data processing algorithm for numerical computations can be simplified.
基金supported by the National Natural Science Foundation of China(No.U22B2072)the Research Project of China Petroleum Science and Technology Innovation Fund(No.2025DQ02-0144).
文摘As the well drilling depth has broken through the 10,000 m in China,accurate measurements of downhole engineering parameters,such as annulus temperature and pressure for the whole wellbore,are significant in controlling potential downhole complexities.In this present work,a new micro-measurer is developed by integrating measurements of downhole temperature,pressure,magnetic field strength,and its own dynamic signals.The micro-measurer can flow with drilling fluid from the drillstring to the bottomhole and then float up back to the ground via the wellbore annulus.Compared with other downhole measurement tools that are fixedly connected to the drill string,its“measure-and-move-on”approach reduces the residence time in the high-temperature and high-pressure zone at the bottomhole;moreover,both the pressure and temperature at different well depth can be measured,thereby the temperature and pressure profiles of the whole wellbore can be constructed.In addition,the bluetooth low energy(BLE)technique is applied to offer the micro-measurer with the capability of wireless information transmission;while hydrodynamic optimization of the micro-measurer is carried out to design the structure of the micro-measurer,which can promote its recovery rate from downhole.In addition,an intelligent joint for releasing micro-measurers from the wellbore annulus is also proposed,aiming to overcome the limitation imposed by the nozzle on the size of the micro-measurer.Both the indoor experiments and the field tests have verified the feasibility of the newly designed micro-measurer,which is a key step for establishing a complete downhole internet of things(IoT)system to serve the intelligent drilling in the future.
