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Role of polyanionic cellulose (PAC)

Release time:

2023-08-26

Source:

reticulation

I. Overview

Poly anionic cellulose (Poly anioniccellulose) abbreviated as PAC, is a water-soluble cellulose ether derivative produced by chemical modification of natural cellulose, it is an important water-soluble cellulose ether, a white or slightly yellow powder, it can be dissolved in water, has good heat stability and salt resistance. The mud fluid formulated with this product has good water loss reduction, inhibition and high temperature resistance. It is used in oil drilling brine wells and offshore oil drilling.

Characteristics of PAC: It belongs to ionic cellulose ether, which has the characteristics of high purity, high degree of substitution, and uniform distribution of substituents. It can be used as thickening agent, rheology regulator, water loss reduction agent, etc. 1.Suitable for mud from fresh water to saturated brine.2.Low viscosity PAC can reduce the amount of filtration loss and does not significantly increase the system viscous liquid, high solids system.3.High viscosity PAC has high slurry making capacity, and the effect of reducing the filtration loss water is obvious.4. It is suitable for low-solid-phase mud and non-solid-phase brine mud.4. The mud stream formulated by PAC can inhibit the dispersion and expansion of clay and shale in high-salt media, thus reducing the pollution of the well wall.5. Excellent mud drilling and workover fluids, and also fracturing fluids.

Application of PAC

1.Application of PAC in drilling fluid.

PAC is ideal to be used as inhibitor and water loss reduction agent. The mud stream prepared by PAC can inhibit the dispersion and expansion of clay and shale in high salt medium, so as to avoid well wall pollution.

2.Application of PAC in well workover fluid.

Well workover fluid formulated with PAC is low solid phase, which does not block the permeability of the production layer due to solids, and will not damage the production layer; and it has low water loss, which reduces the amount of water entering into the production layer, and the entering water will form water town phenomenon due to the emulsion blockage. Well workover fluids formulated with PAC offer advantages not found in other workover fluids. It protects the producing formation from damage; it has the carrying capacity to clean the borehole and reduces the amount of work required to maintain the borehole; it has the ability to resist water and sediment infiltration and rarely foams; it can be stored or transferred between wells, and it is less costly than general mud workover fluids.

3.Application of PAC in fracturing fluid.

The fracturing fluid prepared with PAC can resist 2% KCI solution (added when preparing fracturing fluid) and has good dissolution performance, is easy to use, can be prepared on site, and has fast gel formation speed and strong sand-carrying capacity. It can be used in the formation with low osmotic pressure, and its fracturing effect is good.