约束稀疏脉冲反演在大庆茂兴地区泉四段储层研究中的应用

笔者从约束稀疏脉冲反演技术的基本原理入手,重点说明稀疏脉冲反演在大庆茂兴地区泉四段储层的应用,其基本步骤和方法,如子波估算、初始模型建立和Lambda取值等,为约束稀疏脉冲反演技术的合理应用提供参考.     

Conglomeratic reservoir characterization in the Caiyu field of the Langgu sag, North China

Several subaqueous alluvial fans are developed along the footwall of the northern boundary fault zone—the Daxing fault of the Langgu sag, Bohai Bay Basin, North China. A distinct feature is the significant difference in hydrocarbon enrichment between neighboring wells drilled in the same sedimentary facies. This paper analyses the controlling factors for hydrocarbon accumulation of subaqueous alluvial fan in the Caiyu field, north of the Langgu sag. Based on reprocessed seismic data and using Jason inversion method, the contrast of cross-well correlation panel was established and a reservoir type model was build-up; reservoir heterogeneity was interpreted from inversion impedance data. The result shows six conglomeratic bodies in this fan, which are stacked vertically and laterally. The lithofacies is the key controlling factor for the hydrocarbon accumulation, and diagenesis and tectonic stresses also play important roles in the hydrocarbon enrichment.     

Using Kolmogorov-Smirnov Statistics to Compare Geostrophic Velocities Measured by the Jason, TOPEX, and Poseidon Altimeters

The Kolmogorov-Smirnov (K-S) test is used to compare probability density functions (PDFs) of geostrophic velocities measured by the TOPEX, Poseidon, and Jason altimeters. Velocity PDFs are computed in 2.5° by 2.5° boxes for regions equatorward of 60° latitude. Although velocities measured by the TOPEX and Jason altimeters can differ, on the basis of the K-S test the velocities are statistically equivalent during the ∼200 day period when the satellites followed the same orbit. Full records from TOPEX, Poseidon, and Jason show less agreement, which can be attributed to temporal variability in ocean surface velocities and differing levels of measurement noise.     

Comparison of Sea Surface Heights Derived from Satellite Altimetry and from Ocean Bottom Pressure Gauges: The SW Pacific MOTEVAS Project

A bottom pressure gauge (BPG) was installed in proximity (3.7 km at closest approach) of Jason-1 and formerly TOPEX/Poseidon (T/P) ground track No. 238 at the Wusi site, located ∼ 10 km offshore off the west coast of Santo Island, Vanuatu, Southwest (SW) Pacific. Sea level variations are inferred from the bottom pressure, seawater temperature, and salinity, corrected for the measured surface atmospheric pressure. The expansion of the water column (steric increase in sea surface height, SSH) due to temperature and salinity changes is approximated by the equation of state. We compare time series of SSH derived from T/P Side B altimeter Geophysical Data Records (GDR) and Jason-1 Interim Geophysical Data Records (IGDR), with the gauge-inferred sea level variations. Since altimeter SSH is a geocentric measurement, whereas the gauge-inferred observation is a relative sea level measurement, SSH comparison is conducted with the means of both series removed in this study. In addition, high-rate (1-Hz) bottom pressure implied wave heights (H_1/3) are compared with the significant wave height (SWH) measured by Jason-1. Noticeable discrepancy is found in this comparison for high waves, however the differences do not contribute significantly to the difference in sea level variations observed between the altimeter and the pressure gauge. In situ atmospheric pressure measurements are also used to verify the inverse barometer (IB) and the dry troposphere corrections (DTC) used in the Jason IGDR. We observe a bias between the IGDR corrections and those derived from the local sensors. Standard deviations of the sea level differences between T/P and BPG is 52 mm and is 48 mm between Jason and BPG, indicating that both altimeters have similar performance at the Wusi site and that it is feasible to conduct long-term monitoring of altimetry at such a site.     

基于11年高度计数据的中国海海平面变化初步研究

利用1992年10月~2004年1月共11 a的TOPEX/Poseidon(T/P)和Jason-1高度计数据,对中国海海平面的时空变化变化做了初步分析,并且对11 a间海平面的上升速率进行了分析。研究发现中国海海平面11 a间的一些基本的变化特征:(1)11 a间中国海海平面变化被两次厄尔尼诺-拉尼娜现象分成了5个阶段;(2)中国海海平面变化以1 a周期为主,其中黄海和东海变化较为相似,以1 a周期信号为主,而渤海则还有2个月的周期信号,南海还有0.5 a信号;(3)11 a间,渤海海平面变化振幅最大,黄海和东海次之,南海变化最小,南海海平面变化受厄尔尼诺-拉尼娜事件影响程度最大,黄海和东海次之,渤海最小;(4)中国海海平面的上升速率为0.593 cm/a,渤海、黄海、东海、南海的上升速率依次为0.365,0.517,0.683,0.611 cm/a。分析结果为中国海海平面的变化规律、厄尔尼诺现象对中国海海平面变化的影响以及对未来海平面上升趋势的预测提供了有力的依据。     

测井约束反演技术在老河口油田老163井区的应用

针对老河口油田老163井区新近系河流相油气藏储层纵横向变化大、油气聚集复杂、常规地震解释精度低的问题,利用Jason测井约束反演技术对该地区馆上段储层进行了地震处理及砂体描述。通过地震资料反演前预处理、测井资料标准化校正、合成记录标定层位,GOCAD建模弥补Jason建立初始模型功能的不足,提高了该地区地震解释的精度。结果显示,反演可以识别3～6m的储集层,解决了砂体薄互层识别难的问题,获得了比较好的勘探及开发效果。     

Evidence That Sea State Bias is Different for Ascending and Descending Tracks

Jason-1 and TOPEX/Poseidon (T/P) measured sea-surface heights (SSHs) are compared for five regions during the verification tandem phase. The five regions are of similar latitude and spatial extent and include the Gulf of Mexico, Arabian Sea, Bay of Bengal, and locations in the Pacific and Atlantic Oceans away from land. In all five regions, a bias, defined as Jason SSH—TOPEX-B SSH, exists that is different for ascending and descending tracks. For example, in the Gulf of Mexico the bias for ascending tracks was -0.13 cm and the bias for descending tracks was 2.19 cm. In the Arabian Sea the bias for ascending tracks was -2.45 cm and the bias for descending tracks was -1.31 cm. The bias was found to depend on track orientation and significant wave height (SWH), indicating an error in the sea state bias (SSB) model for one or both altimeters. The bias in all five regions can be significantly reduced by calculating separate corrections for ascending and descending tracks in each region as a function of SWH. The correction is calculated by fitting a second-order polynomial to the bias as a function of SWH separately for ascending and descending tracks. An additional constraint is required to properly apply the correction, and we chose to minimize the sum of the TOPEX-B and Jason-1 root-mean-square (rms) crossover differences to be consistent with present SSB models. Application of this constraint shows that the correction, though consistent within each region, is different for each region and that each satellite contributes to the bias. One potential source that may account for a portion of the difference in bias is the leakage in the wave forms in TOPEX-B due to differing altitude rates for ascending and descending tracks. Global SSB models could be improved by separating the tracks into ascenders and descenders and calculating a separate SSB model for each track.     

Assessment of the Jason Microwave Radiometer's Measurement of Wet Tropospheric Path Delay Using Comparisons to SSM/I and TMI

The Jason microwave radiometer (JMR) provides a crucial correction due to water vapor in the troposphere, and a much smaller correction due to liquid water, to the travel time of the Jason-1 altimeter radar pulse. An error of any size in the radiometer's measurement of wet path delay translates as an error of equal size in the measurement of sea surface height, the ultimate quantity that the altimetric system should yield. The estimate of globally-averaged sea surface height change associated with climate change, requires that uncertainties in the trends in such a global average be accurate to much better than the signal of 1-2 mm/yr. We first compare the JMR observations to those from the TOPEX/Poseidon radiometer (TMR) over approximately six months, since the intent of Jason is to continue the 10-year time series of precision ocean surface topography initiated by T/P. We then assess the stability of the JMR measurement by comparing its wet path delay to those of other orbiting radiometers over 22 months, specifically the Special Sensor Microwave Imager aboard the Defense Meteorological Satellite Program (DMSP-SSM/I) series of satellites, and the Tropical Rainfall Mapping Mission's Microwave Imager (TMI), as well as the European Center for Medium Range Weather Forecasting's (ECMWF) atmospheric numerical model estimate of water vapor. From the combined set, we obtain a robust assessment of the stability of JMR measurements. We find, that JMR is in remarkable agreement with TMR, only 2.5 mm longer, and 6-7 mm standard deviation on their difference in 0.5 degree averages; that JMR has experienced a globally-averaged step-function change, yielding an apparent shortening in wet path delay estimates of 4-5 mm around October 2002 (Jason cycles 28-32); that this step-function is visible only in the 23.8 GHz channel; and that the 34 GHz channel appears to drift at a rate of -0.4K/year. In addition, we find that, while in 2002 there was no evidence of sensitivity to the Jason satellite's attitude (a correlation of the wet path delay with yaw state), in 2003 there are strong (2-3 mm, up to 7 mm globally averaged) changes associated with such yaw state. These JMR issues were all found in the first 22 months of Jason's geophysical data records (GDR) data, and thus they apply to any investigations that use such data without further corrections.     

Comportement de l'oscillateur DORIS/Jason au passage de l'anomalie sud-atlantique

We point out an acceleration of the DORIS clock on-board the Jason satellite during passes over the South Atlantic Anomaly (SAA). When this effect is ignored in the current geodetic positioning of the DORIS stations, derived coordinates show almost linear trends in time, corresponding to anomalous horizontal and vertical velocities of the order of 1 m yr^?1. We propose a simple scientific explanation of this physical phenomenon that is corroborated by direct Jason/TOPEX clock comparisons with respect to the DORIS master beacons in Kourou and Toulouse. To cite this article: P. Willis et al., C. R. Geoscience 336 (2004).     

卫星重力用于南极冰盖物质消融评估

2002年3月发射的GRACE重力卫星,以前所未有的精度和分辨率给出了重力场的时空变化。Jason1重复观测获得海平面的变化,GRACE估计海水质量重新分布引起的海面高变化,两者之差获得比容海面高变化,将该结果与WOA05结果作季节性比较,结果表明CSRRL04,GFZRL04和GRGSGL04三者结果与WOA05结果吻合,优于其他GRACE系列数据。将选取的CSRRL04,GFZRL04和GRGSGL04用于南极冰盖质量变化研究,得到南极冰盖冰雪物质变化的空间分布,结果表明西南极Amundsen区域明显地负增长,南极半岛存在着负增长。估算2003年1月-2007年12月南极冰盖冰雪消融的等效体积变化,变化区间为-76km3/a--69km3/a,对应海平面的贡献变化区间为0.17mm/a-0.21mm/a。