Leakage-proof type temporary blockage additive for low-pressure thin oil well

Abstract

The invention discloses a leakage-proof type temporary blockage additive for a low-pressure thin oil well, which belongs to the field of workover treatment for a thin oil well in petroleum industry. The temporary blockage additive comprise the following raw materials in weight percentage: 0.4-0.6% of hydroxypropyl guar gum, 0.2-0.4% of organic titanium, 5-10% of petroleum resin, 0.3-0.5% of dodecyl dimethyl betaine, 0.1% of sodium sulfite, 0.02-0.04% of ammonium persulfate and 88.5-93.5% of water. The leakage-proof type temporary blockage additive of the invention crosslinks the hydroxypropyl guar gum with the organic titanium to form a gel system, and at the same time adds a certain amount of petroleum resin to form a compound temporary blockage system. The temporary blockage system can immediately break gel without blocking off the oil well, and avoids the accident of stuck pump caused by broken gel fragment. In addition, the leakage-proof type temporary blockage additive has the advantages of no pollution, no harm to a reservoir and low cost.

Description

technical field [0001] The invention relates to the field of thin oil well workover operations in the petroleum industry, in particular to an anti-leakage temporary plugging agent used in low-pressure thin oil wells. Background technique [0002] In the production of low-pressure thin oil wells, due to long-term exploitation, there will be a certain degree of deficit in the formation, so in the process of operation and well washing, a large amount of well killing fluid and well washing fluid will enter the reservoir, so the production of low-pressure thin oil wells often There will be serious leakage problems. After the well killing fluid and well flushing fluid enter the reservoir, it is easy to hydrate and expand the clay minerals, causing water sensitive damage to the reservoir, resulting in a decrease in the permeability of the reservoir, and making it difficult to drain the fluid. Temporary blocking is required. [0003] At present, there are mainly two types of tempo...

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Problems solved by technology

[0004] In the process of realizing the present invention, the inventors found that the prior art has at least the following problems: the polyacrylamide gel system type temporary plugging agent is not easy to degrade and destroy, and it is very easy to damage the formation in the operation of thin oil wells, resulting in a decrease in permeability , resulting in a decrease in liquid production, or even blocking the well, and the polyacrylamide gel shear fragments are easy to get stuck in the pump, affecting the normal production of the oil well; the oil-soluble temporary plugging agent is more expensive, and the well is easily blocked if the amount is large , the dosage is small, it cannot achieve temporary plugging effect, and it is difficult to implement on site. It can only be used in low-permeability reservoirs with little formation deficit.