Abstract

The primary objective of these studies was to quantitatively assess the ground deformation velocities and rates and their natural and man-made controlling factors as the potential risks along the seismically active 70 km section of buried Baku-Tbilisi-Ceyhan Oil, South Caucasus Gas, Western Route Oil and South Caucasus Pipeline Expansion Gas pipelines in Azerbaijan using Persistent Scatterer Interferometric Synthetic Aperture Radar (PS-InSAR) technique.

PS-InSAR analysis showed that the continuous subsidence was prevailing in the kilometer range of 13-70 of pipelines crossing two active seismic faults. The ground uplift deformations were observed in the pipeline kilometer range of 0-13. The minimum and maximum vertical ground movement velocities were observed to be −21.3 mm/y and 14.1 mm/y along 70 km section of pipelines with 250 m buffer zone. Both of these sites were observed at the range of seismic faults. The spatial distribution of sites with ground deformation velocity less than −15 mm/y and more than 15 mm/y was diverse and random all along 70 km of pipelines without any cumulative spatial patterns.

Based on the lower mean, variation and standard deviation of pixel values, the seismic fault in the kilometer range of 21-31 revealed its higher vulnerability to subsidence processes rather than the Seismic Fault in the kilometer range of 46-54. The ground deformation velocities within the range of Seismic Fault KP21-31 revealed the minimum and maximum values of −19.74 mm/y and 14.1 mm/y, respectively whereas at the Seismic Fault KP46-54, the minimum and maximum values were −17.07 mm/y and 9.29 mm/y, respectively.

Encouraging level of agreement with the regression coefficients of 0.92 and 0.96 for known subsiding sites at KP28 + 500 and KP52 + 750 and 0.97 and 0.96 for known uplifting sites at KP04 + 900 and KP35 + 050 respectively was observed between the high-precision GPS and PS-InSAR measurements.

The diverse spatial distribution and variation of ground movement processes along pipelines demonstrated that general geological and geotechnical understanding of the study area is not sufficient to find and mitigate all the critical sites of subsidence and uplifts for the pipeline operators. The prediction of the potential subsidence or uplift locations based on the field visual verifications holds a lot of uncertainties without broad and detailed scale airborne and satellite space observation technologies. The justification of the budget for the geotechnical maintenance activities along long-range oil and gas pipelines requires sophisticated prioritization and planning of the remediation sites and clear quantitative and qualitative risk assessment proving the activeness of these sites and effectiveness of the remediation measures. This means that the PS-InSAR – based approach outlined in this paper is a significant improvement over current ground-based monitoring practices or can significantly contribute them in the initial phase of risk assessment and prioritization.

摘要

这些研究的主要目的是定量评估地下变形速度和速率以及它们的自然和人为控制因素，作为 巴库-第比利斯-杰伊汉潜油，南高加索天然气，西南部地震活跃段70公里处的潜在风险。使用持久散射体干涉合成孔径雷达（PS-InSAR）技术在阿塞拜疆铺设石油和南高加索管道膨胀燃气管道。

PS-InSAR分析表明，在穿越两个活动地震断层的管道的13-70公里范围内，普遍存在连续沉降。在0-13的管道公里范围内观察到地面隆起变形。沿带250 m缓冲区的70 km管道，观察到的最小和最大垂直地面运动速度为-21.3  mm / y和14.1  mm / y 。这两个地点都是在地震断层范围内观察到的。沿地面变形速度小于-15 mm / y和大于15 mm / y的站点的空间分布在整个70 km的管道中是多样且随机的，没有任何累积的空间格局。     

根据像素值的均值，变异和标准偏差较低，在21-31公里范围内的地震断层显示出比在46-54公里范围内的地震断层更容易沉陷。地震断层KP21-31范围内的地面变形速度分别显示出最小值和最大值-19.74  mm / y和14.1  mm / y，而在地震断层KP46-54范围内，最小值和最大值为-17.07  mm / y和9.29  mm / y。

在高精度GPS和KP28  +  500之间，KP28 + 500和KP52  +  750的已知沉降点的回归系数分别为0.92和0.96 ，KP04  +  900和KP35  +  050的已知隆起点的回归系数为0.97和0.96。PS-InSAR测量。

沿管道的地面运动过程的空间分布和变化情况表明，对研究区域的一般地质和岩土技术认识不足以为管道运营者找到并减轻所有沉降和隆升的关键地点。如果没有广泛而详细的机载和卫星空间观测技术，基于现场目测验证的潜在沉降或隆升位置预测将具有很多不确定性。沿长距离油气管道进行岩土维护活动预算的合理性要求对修复地点进行优先级排序和规划，并进行清晰的定量和定性风险评估，以证明这些地点的活跃性和补救措施的有效性。