Sodium carboxymethylcellulose CMC is a water-soluble polymer that can be quickly dissolved in cold or hot water; it is used as a thickener, rheology control agent, adhesive, stabilizer, protective colloid, and suspending agent in oil drilling and mining operations. It is a good drilling mud treatment agent and a material for preparing completion fluids. It has high pulping rate and good salt resistance. For fresh water slurry, sea water slurry and saturated salt water slurry, CMC is an excellent fluid loss reduction treatment agent and has good viscosity improvement ability and high temperature resistance (150°C). It is suitable for preparing fresh water, sea water and saturated brine completion fluids, and can be prepared into completion fluids of various densities under the aggravation of calcium chloride, and can make the completion fluid have a certain viscosity and low filter loss.
1. Application of sodium carboxymethyl cellulose CMC in oil drilling and mining industry
1. 1Application of sodium carboxymethylcellulose CMC in drilling fluids
The non-dispersed system drilling fluid configured with CMC has strong ability to carry drilling cuttings, inhibits the dispersion of clay, reduces the speed of clay slurry, is beneficial to the stability of the well wall, and effectively increases the drilling rate.
The dispersion system drilling fluid configured with CMC has good suspension ability, can accommodate more solid phases, can greatly improve particle stability, is most suitable for preparing high-density drilling fluid, and can efficiently adjust the rheology of the drilling fluid; during drilling A dense, high-quality mud cake can be formed in the liquid, which has excellent filter loss reduction effect and reduces free water.
Calcium-treated drilling fluid configured with CMC has good anti-calcium ability and can prevent excessive flocculation of clay particles in the system caused by calcium ions, allowing the drilling fluid to maintain a good flocculation state and maintain stable solid content and rheology of the drilling fluid. This ensures that the drilling fluid has good and stable performance.
Brine drilling fluids, seawater drilling fluids, and saturated brine drilling fluids configured with CMC have low sensitivity to salt and strong resistance to salt, calcium, and magnesium. They are used as rheology regulators to achieve drilling stability under low dosage conditions. The liquid rheology can be quickly adjusted, and at the same time, it can quickly carry out drill cuttings and maintain a low solid content, which is beneficial to increasing the drilling speed. When used as a fluid loss reducer, it can form a dense mud cake. Since the filtrate filtered out through the filter cake is close to the native water of the formation, the filtrate will cause less damage to the oil and gas layer.
Potassium-based drilling fluid configured with CMC has low sensitivity to potassium salts, calcium salts, and magnesium salts, and can quickly and efficiently adjust the rheology of this type of drilling fluid. It not only has good filter loss reduction effects, but also has excellent drilling cleaning properties. The ability to remove cuttings and clean the drill bit is particularly effective in formations prone to stuck drilling.
The polymer drilling fluid configured with CMC has good compatibility with other polymers and strong suspension ability. It can clean drilling cuttings in a timely and efficient manner. It synergistically keeps the drilling fluid with low solid phase and low dispersion of clay. It is also an excellent reducing agent. Fluid loss agent.
The low solid phase drilling fluid configured with CMC can quickly and efficiently adjust the rheology of the drilling fluid. It has excellent suspension ability and can remove drilling cuttings promptly and efficiently, keeping the drilling fluid with a low solid content, increasing the drilling speed, and stabilizing the well wall. , and has excellent filter loss reduction effect.
The environmentally friendly drilling fluid configured with CMC is green, environmentally friendly, non-toxic, odorless, biodegradable, not prone to corruption during use, the maintenance cost of the drilling fluid is low, and the health and safety of construction workers are guaranteed. It is suitable for various complex applications. Drilling needs of geological conditions, harmless to agricultural production.
2.Application of sodium carboxymethyl cellulose CMC in cementing fluid (completion fluid)
The cement slurry configured with CMC can improve the fluidity of the cementing fluid, giving it a suitable initial viscosity and lower fluid loss. At the same time, it can protect the well wall and prevent fluid from entering pores and fractures.
The sealing fluid configured with CMC can adjust the liquid's fluidity, thixotropy and ability to suspend the solid phase. Since the product has good salt resistance (especially monovalent metal ions), the product is used for cleaning brine-type seals. Liquid effect is obvious.
The workover fluid prepared with the company's CMC has low solid phase, which will not block the permeability of the production layer due to solids and will not damage the production layer; it also has low water loss, which reduces the amount of water entering the production layer and reduces the amount of water entering the production layer. Water can form water ballast due to emulsion blockage. Workover fluids formulated with CMC and PAC provide advantages that other workover fluids do not have. Protect the production layer from permanent damage; have the ability to carry clean wellbore, and reduce the workload of maintaining the wellbore; have the ability to resist water and sediment infiltration, and rarely foam; can be stored or between wells The cost is lower than that of ordinary mud workover fluid due to its time-to-use conversion.
3. Application of sodium carboxymethyl cellulose CMC in fracturing fluid
The fracturing fluid prepared with CMC can quickly increase the viscosity of the fracturing fluid, efficiently carry proppant into the oil well fractures, establish permeability channels, quickly reduce filtration loss, rapidly increase formation pressure, and achieve the effect of efficiently transmitting pressure. The product No residue, no damage to the bottom layer, high pumpability, low wear resistance, and a certain ability to carry proppant.
