Delay gelatinizing composite plugging liquid and preparation method thereof

Abstract

The invention provides a delayed gelatinizing composite plugging liquid and a preparation method thereof, and the method comprises the following steps: adding 0-1.0% of a delay agent into 100% of fresh water according to the total percentage of fresh water, continuously adding 1-10% of a polymer suspending agent A and 0.5-3% of a polymer suspending agent B after the delay agent is dissolved, continuously adding 0.1-3% of a cross-linking agent after the polymer suspending agent is dissolved, and uniformly stirring to obtain the delayed gelatinizing composite plugging liquid. And then sequentially adding 50-100% of a curing main agent, 5-20% of a curing auxiliary agent, 0-100% of a density regulator, 0-2% of an activating agent and 0-3% of a retarder, and stirring for 20-60 minutes at the speed of 800r / min until solid-phase particles are uniformly dispersed, thereby obtaining the water-dispersion-resistant delayed gelatinizing composite plugging liquid suitable for the high-temperature fractured formation. The plugging working fluid disclosed by the invention is good in pumpability, controllable in crosslinking time and curing time, capable of resisting the temperature of 150 DEG C or above, simple in construction process and applicable to plugging operation in the high-temperature deep stratum drilling process.

Description

technical field [0001] The invention relates to the technical field of materials, in particular to a delayed-gel-forming composite leakage plugging fluid suitable for water-resistant dispersion of high-temperature fractured formations and a preparation method thereof. Background technique [0002] Loss of circulation is one of the most common and difficult downhole complex accidents in the drilling process. It has a very serious impact on oil well safety, personal safety and drilling construction. Once lost circulation occurs, it will complicate the downhole environment, which will not only reduce the drilling speed, delay the drilling schedule, but also affect the daily maintenance of drilling fluids, disturb the geological logging, damage the oil and gas layers and reduce the production efficiency, thereby bringing about huge economic loss. Efficient control of lost circulation accidents can ensure personal and equipment safety, improve drilling speed, and save the econom...

AI Technical Summary

Problems solved by technology

However, during the drilling process, cement slurry is used for plugging, and there is a risk of cement slurry and drilling fluid contact pollution, which may lead to additional downhole complex accidents such as flash coagulation and early thickening of the slurry

The slag-based solidified plugging fluid has good compatibility, can be set and hardened, has good fluidity, and has high strength after solidification, but it is easy to lose in the fracture, difficult to stay, and has poor resistance to formation water dilution

In order to ensure that the plugging fluid stays in the crack and quickly condenses to form strength, it is necessary to add a large amount of activator; after adding a large amount of activator, the pumping time will be greatly shortened under high temperature and ultra-high temperature conditions, and a large amount of retarder must be added to ensure pumping. The safety of the process makes it difficult to reconcile the coagulation time and the pumping safety time, and faces the problem of conflict between the amount of activator and retarder

[0005] At present, the polymer gel is usually used first, and the inorganic gel plugging material is used later, and the construction process is cumbersome.

Images