Injection method capable of increasing steam huff and puff recovery ratio of heavy oil well

Abstract

The invention provides an injection method capable of increasing the steam huff and puff recovery ratio of a heavy oil well. The injection method capable of increasing the steam huff and puff recovery ratio of the heavy oil well includes the steps that an accompanied injection agent solution is prepared according to the accompanied injection agent quantity needed by different wells; before steam is injected into the oil well, 1 / 5-1 / 3 of the accompanied injection agent solution in the designed quantity is injected into the well, then steam injection is conducted, 1 / 5-1 / 3 of the accompanied injection agent solution is then injected when the quantity of the injected steam reaches 1 / 7-1 / 4 of the designed steam injection quantity, the remaining accompanied injection agent solution is injected when the quantity of the injected steam reaches 2 / 7-1 / 2 of the designed steam injection quantity, the remaining steam continues to be injected, and the injection procedure is completed; and soaking is conducted, and recovery is conducted after soaking. Through the injection method capable of increasing the steam huff and puff recovery ratio of the heavy oil well, the viscosity of heavy oil in an oil deposit can be effectively reduced, the periodic oil production rate of the oil well is increased, and the oil-steam ratio, the production-injection ratio and the water recovery rate are substantially increased after the measures are taken compared with those before the measures are taken.

Description

technical field [0001] The invention relates to the technical field of oil recovery in oil fields, in particular to an injection method for increasing steam huff and puff recovery of heavy oil wells. Background technique [0002] At present, the development of heavy oil is dominated by steam huffing and puffing, accounting for about 80% of the total output of heavy oil. Steam huff and puff has the effect of increasing production of almost all types of heavy oil reservoirs, and the annual oil recovery rate is several times that of conventional oil recovery methods, generally reaching 3% to 8%. But generally after several cycles of continuous throughput, the increase of water saturation will increase the oil-water ratio, increase the formation deficit, decrease the formation pressure, accelerate the decline of production, reduce the oil-steam ratio year by year, and the economic benefits will become worse day by day. For this reason, we have invented a new injection method to...

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Problems solved by technology

But generally after several cycles of continuous throughput, the increase of water saturation will increase the oil-water ratio, the formation deficit will increase, the formation pressure will drop, the decline rate of production will accelerate, the oil-gas ratio will decrease year by year, and the economic benefits will become worse.

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