Acidification, as a stimulation measure for oil and gas fields, is commonly used in carbonate and sandstone formations. In the process of conventional acidification operations, there are often phenomena such as high acid loss, fast acid rock reaction rate, and severe corrosion of underground pipe columns, which can only eliminate damage near the wellbore and are difficult to achieve effective results for deep acidification. Slow release acid can effectively reduce the reaction rate of acid rock, increase the acid release distance, effectively achieve deep acidification of the formation, and increase oil and gas production.
The main reaction process of acidification includes: 1) the production of active H+in the liquid phase; 2) The diffusion of active H+towards the rock surface; 3) H+reacts with the rock surface. If any step of the reaction in the above process can be slowed down, it can effectively slow down the reaction rate of the acid, extend the action time of the active acid, and thus achieve the goal of slow acid release. The sustained-release mechanism of autogenic acids is achieved by controlling the production of active substances. The speed of H+, the slow release mechanism of thickening acid and enveloping acid is to control the diffusion speed of H+, and the slow release of foam acid and emulsified acid is achieved by controlling the reaction rate of active H+and rock surface.
Post time: Oct-19-2023