Short-injection water injection well acidation injectivity process

Abstract

The invention discloses a short-injection water injection well acidation injectivity process for petroleum industry, which is applied to a short-injection water injection well, improves the acidation effect and improves the water injection success rate. The process comprises the following steps: a prepose acid liquor soaking oil layer is inputted; the well is backwashed at high flow rate so as to discharge the prepose acid liquor; main acid is squeezed in; the well is backwashed by water mixed with gas, the back pressure on the bottom of the well is reduced, the ground layer is induced to flow, and the deep stoppage reactant can be discharged under the effect of the strata pressure. The prepose acid liquor is discharged through the repeated washing of the well, so the effect of the main acid is adequately played, the secondary pollution of the oil layer can be prevented, the deep acidation can be realized, the injectivity valid period is prolonged, the measure success rate is improved, and the recovery rate of the low-permeability reservoir can be improved. The effect of the used acid can be effectively played, the underground tube pile can be free from damaged, the consumption of the main acid can be reduced on the premise of ensuring the construction effect, and the production cost can be saved.

Description

technical field [0001] The invention belongs to an oil production and water injection technology method in the petroleum industry, in particular to an acidification and injection enhancement process for under-injection water injection wells, which is used in under-injection water injection wells to improve the acidification effect and the success rate of water injection. Background technique [0002] With the deepening of oilfield development, oilfield water injection becomes increasingly important. As one of the commonly used technologies for oil layer stimulation, the acidizing injection stimulation technology of water injection wells uses acid to dissolve the blockages in the rock pores or certain mineral components of the bedrock itself, thereby improving the connectivity of the pores inside the rock and removing the pollution near the well wall , Improve the water injection capacity. [0003] At present, in order to improve the water injection effect of under-injection...

AI Technical Summary

Problems solved by technology

[0005] First, during the construction process, the main acid liquid reacts with the scale layer on the inner wall of the oil pipe, resulting in the consumption of acid liquid, reducing the utilization rate of acid liquid, and increasing the pH value, which affects the acidizing effect

[0006] Second, for deep polluted wells, the injection effect is not good

Acid cannot effectively penetrate deep into the formation

Despite the use of acids such as tardiac, the desired effect was not achieved

[0007] The third is that during the sandstone acidification and acid rock reaction process, the precipitation of reaction products is very easy to form, and the solid precipitation will block the pores, causing secondary damage of acidification

[0009] Due to the existence of these problems, the effective period of stimulation injection is short and the input cost is high, resulting in the waste of tool materials and operating costs, which affects the water injection development of low permeability reservoirs

[0010] If the surface booster pump is used for additional injection, the continuous high-pressure water injection will cause certain damage to the casing