Sand-flushing well-cleaning agent for oil well

Abstract

The invention relates to a sand-flushing well-cleaning agent for an oil well applied to an oil field, which comprises the following components in percentage by weight: 12.5-13.5% of nonyl phenol polyoxyethylene ether sodium sulfate, 6.5-7.0% of fatty acid single glycollic amide polyoxyethylene ether sulfate, 10.5-11.0% of alkyl phenol polyoxyethylene ether (10) sodium sulfate, 5.5-6.0% of alkyl phenol polyoxyethylene ether carboxylate, 4.5-5.0% of ammonium bicarbonate and the rest of water. The sand-flushing well-cleaning agent disclosed by the invention has the effects that 0.5-1.0% of sand-flushing well-cleaning agent for the oil well is added in the water to obtain sand-flushing well-cleaning agent for an oil well liquid; and after the sand-flushing well-cleaning agent is utilized for sand-flushing well-cleaning construction, the sand flushing efficiency can be improved by 50-73%.

Description

technical field [0001] The invention relates to the field of oil recovery technology, in particular to an oil well sand flushing agent and a preparation method thereof. Background technique [0002] With the deepening of oilfield development, sand production is serious in some oil layers, and sand washing operations need to be carried out at regular intervals. Oil fields used to use sewage to wash wells and sand in the sand washing process. However, during the sand washing process, the well washing fluid leaked into the oil layer, the sand washing was not complete, and the sand was returned to the oil layer. [0003] Research on oil well negative pressure sand washing device published by Li Shuzhen in the 03 issue of "Petroleum Field Machinery" in 2004 Aiming at the problems of well washing fluid leaking into the oil layer and sand settling back to the oil layer in the normal sand washing process, a negative pressure sand washing device is designed. Pressure sand flushing d...

AI Technical Summary

Problems solved by technology

In addition, after the heavy oil thermal recovery well enters the high-period huff and puff production stage, the formation pressure drops greatly, and the formation energy cannot be replenished, resulting in a serious formation deficit, the formation pressure is lower than the wellbore fluid column pressure, and the liquid cannot return to the wellbore or cannot The sand is washed out of the ground, causing the oil well to fail to produce normally. Therefore, it is urgent to solve the problem of sand flushing in leakage wells in heavy oil thermal recovery