在综合分析传统单纯形法及目前微地震定位算法选用的各类速度模型及其相关误差的基础上,提出一种无需测速和反演的速度模型,并基于此对传统单纯形法进行微地震定位改进研究,结合不同速度模型、不同迭代算法在差异化速度误差和速度各向异性变化条件下的定位精度进行算例分析和工程验证,研究结果表明:无需测速和反演的速度模型能有效避免传统速度反演模型在速度反演过程中的方法误差和现场测速造成的测速误差,将其应用于传统单纯形法,不仅能有效避免传统单纯形法易陷入局部最优的问题,充分发挥单纯形法迭代易收敛的优势,且对于检波器阵列外的震源进行定位时相比其他迭代方法求解时定位精度显著提高,可为微地震定位领域提供一种新的研究思路。
A new type of velocity model without the velocity inversion and velocity measuring was put forward for the improvement of the traditional simplex method based on the comprehensive analysis of the traditional simplex method,the velocity models and the related errors of the microseism locating method. Numerical analysis and engineering validation on the precision of locating under the conditions of different velocity models,different iteration algorithms with velocity errors and velocity anisotropy were carried out. The results show that the new velocity model can effectively avoid the errors happened in the process of velocity inversion and measuring and avoid the problem of local minimum in traditional simplex method. In comparison with the other iterative methods, significantly higher accuracy of locating the seismic sources outside the sensor arrays is achieved,taking advantage of the easy convergence of iterations of the simplex method.
