A kind of sticking construction method

Abstract

The invention discloses an attaching and blocking construction method. The attaching and blocking construction method includes the following steps that the step of well descending of a construction pipe column is conducted, wherein the construction pipe column is put into a well; the step of first reverse buckling is conducted, wherein first reverse buckling refers to forward rotation of an oil pipe, due to the fact that a release tool is connected with the oil pipe in a forward buckling manner, the release tool cannot disengage from the oil pipe, the release tool is connected with an attaching and blocking pipe in a reverse buckling manner, the attaching and blocking pipe can disengage from the release tool, and reverse buckling is completed; the step of judging whether reverse buckling succeeds or not is conducted, wherein whether releasing succeeds or not is judged through well washing pressure, if the well washing pressure is lower than the pressure before reverse buckling, reversebuckling succeeds, and if the well washing pressure is not changed, the oil pipe is forwards rotated continuously to be released; and the step of later ash injection is conducted, wherein a cement slurry blocking agent is downwards injected from the oil pipe, cement slurry enters the attaching and blocking pipe from the oil pipe through an inner pipe, due to the effect of a unidirectional leathercup, the cement slurry can only enter the ring-shaped space of the attaching and blocking pipe and a casing pipe from a check valve, and attaching and blocking strengthening construction is conducted. By means of the attaching and blocking construction method, due to first reverse buckling and later ash injection, the time for the cement slurry to embrace the construction pipe column is shortened; whether release succeeds or not is judged through a pressure signal, and the risk that the pipe column is stuck by cement is eradicated; the success rate of attaching and blocking construction is greatly increased, the attaching and blocking construction safety requirement can be met, and the application effect on ultra deep well attaching and blocking is the best.

Description

technical field [0001] The invention relates to the technical field of casing damage treatment of oil-water wells, in particular to a plugging construction method. Background technique [0002] After the oil and water well casing is damaged, it is necessary to use the casing patching method to patch up the broken part of the casing to prevent casing leakage. At the leakage or to be sealed, the construction pipe string and the plugging pipe string are connected with a hand-off tool; during construction, after the cement slurry is poured into the annular space between the casing and the supplementary pipe, the construction pipe string and the supplementary pipe are connected by the hand-off tool. After the column is separated, the excess cement slurry is washed out by the fresh water circulating well fluid, and the construction pipe string is lifted out of the wellbore, and the plugging pipe is solidified by the cement slurry, so that the casing and the patching pipe are conso...

AI Technical Summary

Problems solved by technology

This method uses the expansion cone to expand and fit the expansion tube on the original casing to repair the casing damage, but it cannot strengthen the cement sheath outside the casing, and the cost is high, and the cost performance is very low

[0006] At present, the release method of the release tool is positive rotation release. The key point is that the neutral point of the string load needs to be placed at the release tool when undercutting. If the neutral point is not placed at the release tool, the release point will be under pressure or The impact of pulling force makes it difficult to release and takes a long time to release

Since the construction process is to inject ash first and then buckle, that is, when the buckle is released, the fluid outside the hand tool is cement slurry. If the time of hand removal is too long, the cement slurry will condense and the pipe string will not be disconnected, resulting in the scrapping of the well.

During the construction process, especially when plugging in deep wells, since the load of the construction string is much greater than the load of the plugging string, it is difficult to select the neutral point. At the same time, it is difficult to judge whether the release is successful based on the change of load after back-off; multiple back-offs greatly extend the During the time when the pipe string is in the well, it is very easy to cause construction accidents of cement stuck in the pipe string in the past construction where the ash is injected first and then reversed.

[0007] When faced with a well condition where the oil layer to be repaired and the sealing section is buried too deep (greater than 2800m), three problems will occur: ①The well temperature is too high (90-110°C), which makes the cement slurry prone to flashing; ② The construction pipe string is too long, and the load is too heavy compared with the plugging pipe string, which makes it difficult to select the neutral point; ③It is difficult to judge whether the release is successful

At present, for such problematic wells, the general treatment method is to wash the well with large displacement of clean water to cool down the oil layer or use high-temperature retarding plugging agent for construction. However, because the load of the construction string is much greater than the load of the plugging string, it is impossible to judge whether the undercut is successful. , there are problems such as low construction efficiency, slow cooling time, high cost, etc., which do not meet the construction requirements of oil production plants to reduce costs and improve quality

Images