Multi-round polymer gel deep fine profile control method

Abstract

The invention discloses a multi-round polymer gel deep fine profile control method. According to the method, slugs having different functions are injected in multiple rounds, so that deep profile control can be realized. According to the functions of the slugs in deep profile control, the slugs are classified into four types: the I slug which is a gel flow-guiding agent capable of guiding gel and makes preparations to make the gel enter the stratum; the II slug which is the weak gel for assisting the blocking, effectively connects the gel flow-guiding agent and medium and strong gel, and guarantees that the fluid can effectively and continuously enter the stratum; the III slug which is the medium and strong gel used for medium and deep blocking; and the IV slug which is weak gel used for disturbing flows. During a using process, the I, II and III slugs are injected as required in the first round; the II and III slugs are repeatedly used in the second (third) round; the next injection round is performed after injection requirements are met according to pressure and working parameters; and the IV slug is injected in the last round. The method is more targeted as the slugs are finely injected in multiple rounds, a longer responding period is achieved, the water absorption status of a reservoir is effectively improved, the utilization rate of injected water is improved, the swept volume is enlarged, and finally the oil displacement efficiency is improved. The method has an obvious oil increasing effect, is simple and easy to carry out, is suitable for filed construction, and is especially suitable for wells which have multiple small layers to be explored, are large in interlayer difference, and have high water content; the profile control success rate can be improved to be 90%; the validity period can be prolonged by one year or two years; and the method has a wide popularization and application prospect.

Description

technical field [0001] The invention relates to a production-stimulating measure in IPC classification E21B soil layer or rock drilling technology, especially a multi-round polymer gel deep fine profile control method. Background technique [0002] Continental oil layers are the main oil layers in my country, and one block has multiple layers is one of its characteristics. Water injection development is the main development method of oilfields in my country. In the initial stage of oilfield development, the method of combined injection and production of all wells is generally used for production, that is, the development of a set of injection and production well patterns. In this development mode, due to the inherent heterogeneity of the oil layer itself, there will be interlayer conflicts, that is, interlayer interference, that is, due to the different permeability of the oil layers, when the whole well is flooded, the formation with high permeability will absorb less wate...

AI Technical Summary

Problems solved by technology

However, due to the non-wetting properties of the profile control agent and the formation rock, it is difficult for the profile control agent to enter, and it is often forced to enter by increasing the pressure of the injection system.

In fact, most of the profile control agents are still stuck in the near-wellbore area, resulting in severe blockage in the near-wellbore area and empty pores in the deep reservoir, high water flooding pressure and low oil well energy