The Study Of The Causes And Prevention Methods Of Casing Damage Of Southern XingShuGang Oil Field

By the research of the temporal and spatial distribution of casing damage in the study area, This article improves that temporal and spatial distribution and causes of casing damage vary with the different stages of development, casing damage in the initial distribute in the side of the fault, vertical casing damage points mostly distribute near the top perforation, and mainly to injection wells. With the development of infill adjustment, the increase casing damage wells of developed-layer distribute in the entire zone, and also casing damage horizons increase, casing damage points extend from the perforated top sector to the perforation of the wells gradually. By the research of geological factors, combined Dobby caliper information, logging curve, and Lead-information, the new methods of understanding casing damage layer are set by application of the concept of the main shear and the casing damage horizons are accurately determined by using this method in study the formation of casing damage on SaI ,SaII. Under the circumstances of clearly rock mineral composition and mechanical parameters of casing manage parts ,the author make a new awareness of rock properties of casing damage for Nen-2 index bed, Sal-Sail sandwich, and establish a geological model of casing damage, then clearly understand that the rock itself is a set of internal reason for casing damage. Through the study of the relationship between development process and casing damage, it is defined that the pressure distribution of uneven is the main causes of casing damage of reservoir. The author also understand the stress distribution of the casing damage site according to the indoor experiments of the core stress features. In order to study the mechanical conditions of casing damage and provide sets of quantitative analysis for prevention technologies of casing damage, a set of casing damage shear mechanical model is determined and the mechanical conditions of instability of formation or fault are defined. According to the geological model of casing damage and shear mechanical model, the author analyzes the mechanical process of casing damage in the Sa I -Sa II dissection. Through the related research of the distribution of stress and casing damage, through theoretical calculations and the actual monitoring, the author interprets quantitatively reasonable water pressure and the pressure difference limits in the study area, which provide a reliable basis for the development adjustment. Through the mechanism research, the author supply corresponding measures, such as not perforating Sa II1 of new wells and controlling injection pressure of old wells, which provides a set of technical support for controlling the rate of casing damage.