The In-Situ Stress Analysis of Casing Damage Wells in the Sixth Middle District Based on Kriging Interpolation Method

摘要

Casing damage is a common engineering problem, the causes of which mainly include two aspects: geological factors and engineering factors. In this paper, the application of the data of logging and hydraulic fracturing gives the calculation model of stress in three directions in the sixth middle district, and have an interpolation calculation on the in-situ stress data in the casing damage wells based on the Kriging interpolation method, and then have a study on the casing damage problems of the sixth middle district in Karamay oil field from the perspective of the in-situ stress. The results show that: the triangular nose anticlinal structure of the sixth middle district which is influenced by tectonic stress obviously is typical nonuniform loading zone; the horizontal stress is the biggest, the ratio of the two horizontal stress is 1.58, which is the major cause of the casing diameter shrinkage. According to the characteristics, of the horizontal stress which is too big and the non-uniform load, it is proposed to abandon the conventional design methods of casing string in uniform load, using the non-uniform loading conditions to design, which lays the foundation for secure and stable development of the sixth middle district reservoir.