A kind of high-efficiency selective water shutoff agent for oil field and preparation method thereof

Abstract

The invention belongs to the technical field of oil-field applied chemistry, and provides an efficient selective water plugging agent for oil fields and a preparation method of the efficient selective water plugging agent for the oil fields. The preparation method comprises the following steps of sequentially adding 18.0 percent to 22.0 percent of nonionic monomers, 10.0 percent to 14.0 percent of anionic monomer 1#, 4.0 percent to 8.0 percent of anionic monomers 2# and 2.0 to 4.0 percent of cationic monomers into a flask containing deionized water under the protection of nitrogen, and stirring sufficiently; adding 0.1 percent to 0.2 percent of crosslinking agent 1# and 0.1 percent to 0.15 percent of crosslinking agent 2#, and stirring sufficiently; adding 0.2 percent to 0.3 percent of oxidizing agent and 0.1 percent to 0.2 percent of reducing agent; reacting at a normal temperature for 30 min to obtain water plugging agent gel; purifying the gel and drying, and grinding the agent into products with different particle sizes according to requirements so as to prepare an expansive organosilicon selective water plugging agent. The water plugging agent prepared according to the method provided by the invention has the advantages of higher water plugging efficiency and lower oil plugging ratio, stability in performance at the normal temperature, strong acid resistance and strong inoxidizability, and the water plugging agent can be prepared into products with different particle sizes according to the size of formation pores. The prepared water plugging agent can be used for plugging water from producing layers during the production process and plugging water during the water injection and profile control process.

Description

technical field [0001] The invention belongs to the technical field of oilfield applied chemistry, and relates to the preparation and application of a water shutoff agent for producing water from production layers during the development of oil and gas fields, and in particular to the plugging of water from different water layers in oil and gas fields, and the plugging of water from oil layers in the late stage of oil and gas field development. Background technique [0002] In the process of oilfield development, the water out of the oil layer will seriously affect the oilfield development work, and even reduce the ultimate recovery rate of the oilfield. After the oil well produces water, firstly determine the water level, and then use the water shutoff method to seal it. The purpose of water plugging is to control the flow of water in the water-producing layer and change the flow direction of water in the water flooding oil, improve the efficiency of water flooding, and try ...

AI Technical Summary

Problems solved by technology

[0003] Chemical water blocking is a commonly used water blocking method. Now there are selective blocking agents such as polymer blocking agents, foam blocking agents, oil-based blocking agents, and alcohol-based blocking agents. However, the current water blocking agents have high costs, Disadvantages such as complex operation process, poor selectivity, and susceptibility to salt and calcium pollution

For example, the effective period of the foam water blocking agent is short and the operation process is relatively complicated. Please refer to the application number 201010140446.6, the invention name is a water blocking agent with dual functions and its injection method; the production cost of the oil-based blocking agent is high and the environmental pollution is relatively large. ; Alcohol-based plugging agents are complex to operate and poor in water plugging effect; some polymer plugging agents have poor anti-mineral pollution ability, and cause a significant drop in oil layer productivity

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