A simulation evaluation method for acidification of carbonate heavy oil reservoirs

Abstract

The invention relates to a simulation evaluation method for acidification of carbonate heavy oil reservoirs, comprising: i) sample preparation and parameter determination: taking a core sample of the reservoir reservoir, washing the core sample with oil, and then displacing the core with crude oil The acidification simulation experiment core is prepared; ii) linear flow acid corrosion hole simulation and acidification evaluation: use the acid solution to carry out linear acidification on the acidification simulation experiment core described in step i), measure various parameters, and then use the three-dimensional imaging analysis system to analyze the The above core is scanned to obtain the three-dimensional digital map of the acidification hole, and finally the tortuosity factor is obtained through analysis; iii) Radial flow acidification hole simulation and acidification evaluation: the acidification simulation experiment core described in step i) is carried out radial flow with acid liquid Acidizing ends after the radial breakthrough. The 3D imaging analysis system is used to scan the cross-section of the core, and the obtained acid etching image is analyzed to obtain the fractal dimension.

Description

technical field [0001] The invention belongs to the technical field of oil and gas field development, and relates to an acidification simulation evaluation method for carbonate heavy oil reservoirs. Background technique [0002] Acidizing is one of the effective measures to increase the production of carbonate rock reservoirs. Due to the complex reaction mechanism between acid and carbonate rock, there are many influencing factors, and because of the unstable dissolution phenomenon in the acidizing process, that is, acid erosion wormholes, the carbonic acid It is difficult to predict parameters such as the effective action depth of acid liquid in the acidizing process of salt rock by pure theoretical calculation methods, and the optimization of construction parameters and effect prediction must also rely on indoor simulation methods. [0003] At present, there is no unified standard for carbonate rock acidification simulation evaluation. Usually, the linear displacement expe...

AI Technical Summary

Problems solved by technology

[0003] At present, there is no unified standard for carbonate rock acidification simulation evaluation. Usually, the linear displacement experiment is used to measure the breakthrough time and breakthrough volume of acid liquid, which can reflect the impact of core mineral distribution and pore throat structure on acidification to a certain extent. However, it is impossible to determine the morphological characteristics of acid-etched vugs in the radial flow of acid liquid, and only approximate methods can be used to deal with it, and it cannot reflect the influence of formation fluid properties on the formation and expansion of acid-etched vugs. However, for heavy oil reservoirs, since the crude oil contains colloidal asphaltenes, it is difficult for the acid liquid to contact the rock wall under formation conditions, which affects the acid-rock reaction, thereby affecting the formation and expansion of acid-etched pores. Conventional indoor acidification simulation evaluation method, the prediction results and the actual will inevitably have a large difference

Images