Cement fluid loss

J. F. Baret. Why cement fluid loss additives are necessary. In Proceedings Volume, pages 853-860. SPE Petrol Eng Int Mtg (Tianjin, China, 11/1-11/4), 1988. 

L. K. Moran and T. R. Murray. Well cement fluid loss additive and method. Patent US 5009269,1991. 

D. T. Muller. Performance characteristics of vinylsulfonate-based cement fluid-loss additives. In Proceedings Volume, pages 609-617. SPE Rocky Mountain Reg Mtg (Casper, WY, 5/18-5/21), 1992. 

P. Schilling. Aminated sulfonated or sulfomethylated lignins as cement fluid loss control additives. Patent US 4990191, 1991. 

S. Schilling. Lignin-based cement fluid loss control additive. Patent US 4926944, 1990. 

An interesting and separate application proposed for borate is as a component of a cement fluid loss additive. Cements require a minimum amount of water for proper hydration and setting and if water from the cement filters into the formation, the setting process can be compromised. Cements therefore contain fluid loss additives. A dried, preformed borate cross-linked polyvinyl alcohol (PVA)-sorbitol complex has been proposed for use as a fluid cement fluid loss additive [100]. This may have wider application in other oil well fluids. 

Polyacrylamides are used in many other oilfield appUcations. These include cement additives for fluid loss control in well cementing operations (127), viscosity control additives for drilling muds (128), and fracturing fluids (129). Copolymers [40623-73-2] of acrylamide and acrylamidomethylpropanesulfonic acid do not degrade with the high concentrations of acids used in acid fracturing. 

An injectivity test is performed using clean, solids-free water or brine. If a low fluid loss completion fluid is in the hole, it must be displaced from the perforations before starting the injecting. This test will give an idea of the permeability of the formation to the cement filtrate. 

Fluid loss additives are also called filtrate-reducing agents. Fluid losses may occur when the fluid comes in contact with a porous formation. This is relevant for drilling and completion fluids, fracturing fluids, and cement slurries. 

Two stages are considered with respect to the fluid loss behavior of a cement slurry [140] ... 

Static experiments with pistonlike filtering can be reliable, however, to obtain information on the fluid loss behavior in certain stages of a cementation process, in particular when the slurry is at rest. 

A water-soluble polymer of monoallylamine can be used in conjunction with a sulfonated polymer, such as a water-soluble lignosulfonate, condensed naphthalene sulfonate, or sulfonated vinyl aromatic polymer, to minimize fluid loss from the slurry during well cementing operations [1510,1511]. The polymer... 

In hydraulic cement slurries, fluid loss additives based on sulfonated or sulfomethylated lignins have been described. 

The fluid loss and thickening time characteristics of the cement slurry is altered, either by increasing the molecular weight of the lignin by cross-linking with formaldehyde or epichlorohydrin or by adding agents such as sodium sulfite, sodium metasilicate, sodium phosphate, and sodium naphthalene sulfonate. 

A polymeric composition for reducing fluid loss in drilling muds and well cement compositions is obtained by the free radical-initiated polymerization of a water-soluble vinyl monomer in an aqueous suspension of lignin, modified lignins, lignite, brown coal, and modified brown coal [705,1847]. The vinyl monomers can be methacrylic acid, methacrylamide, hydroxyethyl acrylate, hydroxypropyl acrylate, vinylacetate, methyl vinyl ether, ethyl vinyl ether, N-methylmethacrylamide, N,N-dimethylmethacrylamide, vinyl sulfonate, and additional AMPS. In this process a grafting process to the coals by chain transfer may occur. 

Homopolymers and copolymers from amido-sulfonic acid or salt containing monomers can be prepared by reactive extrusion, preferably in a twin screw extruder [1660]. The process produces a solid polymer. Copolymers of acrylamide, N-vinyl-2-pyrrolidone, and sodium-2-acrylamido-2-methyl-propane sulfonate have been proposed to be active as fluid loss agents. Another component of the formulations is the sodium salt of naphthalene formaldehyde sulfonate [207]. The fluid loss additive is mixed with hydraulic cements in suitable amounts. 

A terpolymer fonned from ionic monomers AMPS, sodium vinyl sulfonate or vinylbenzene sulfonate itaconic acid, and a nonionic monomer, for example, acrylamide, N,N-dimethylacrylamide, N-vinylpyrrolidone, N-vinyl acetamide, and dimethylaminoethyl methacrylate, is used as a fluid loss agent in oil well cements [1562], The terpolymer should have a molecular weight between 200,000and 1,000,000 Daltons. The terpolymer comprises AMPS, acrylamide, and itaconic acid. Such copolymers also serve in drilling fluids [1892]. 

A fluid loss additive useful in cementing oil and gas wells is a blend [423,424,1015] of a copolymer of acrylamide/vinyl imidazole. The second component in the blend is a copolymer of vinylpyrrolidone and the sodium salt of vinyl sulfonate. Details are given in Table 2-2. The copolymers are mixed together in the range of 20 80 to 80 20. Sodium or potassium salts or a sulfonated naphthalene formaldehyde condensate can be used as a dispersant. 

An N-vinylpyrrolidone/acrylamide random copolymer (0.05% to 5.0% by weight) is used for cementing compositions [371, 1076]. Furthermore, a sulfonate-containing cement dispersant is necessary. The additive can be used in wells with a bottom-hole temperature of 80° to 300° F. The fluid loss additive mixture is especially effective at low temperatures, for example, below 100° F and in sodium silicate-extended slurries. 

Copolymers of styrene with AMPS having fluid loss capabilities for use in well cementing operations have been described [254]. The styrene is present... 

Lignin amines with high nitrogen content are water soluble at both alkaline and acidic pH values. The lignin amines have various useful properties. For example, they are active as flocculants, filtration aids, scale inhibitors, fluid loss additives, oil well cement additives, and corrosion inhibitors among other potential uses. The nitrogen is introduced into the lignins with the Mannich reaction [1570]. 

The cement usually is mixed dry with the additives. Depending on the application of the cement, a wide variety of additives can be incorporated. These include accelerators, retarders, dispersants, extenders, weighting agents, gels, foamers, and fluid loss additives. 

However, the mechanism of action of filtration control additives is not yet completely understood. Examples are bentonite, latex, various organic polymers, and copolymers. Many additives for fluid loss are water-soluble polymers. Vinyl sulfonate fluid loss additives based on the 2-acrylamido-2-methyl-propane sulfonic acid (AMPS) monomer are in common use in field cementing operations [363]. The copolymerization of AMPS with conjugate monomers yields a fluid loss agent whose properties include minimal retardation, salt tolerance, high efficiency, thermal stability, and excellent solids support. 

Gilsonite is active as a fluid loss additive because the permeability of cement is reduced. Latex additives also act as fluid loss additives. They also act as bonding aids, gas migration preventers, and matrix intensifiers. They improve the elasticity of the cement and the resistance to corrosive fluids [921]. A styrene-butadiene latex in combination with nonionic and anionic surfactants shows less fluid loss. The styrene-butadiene latex is added in an amount up to 30% by weight of the dry cement. The ratio of styrene to butadiene in the latex is typically 2 1. In addition, a nonionic surfactant (octylphenol ethoxylate and polyethylene oxide) or an anionic surfactant, a copolymer of maleic anhydride, and 2-hydroxypropyl acrylate [719] can be added in amounts up to 2%. 

V. G. Boncan and R. Gandy. Well cementing method using an AM/AMPS fluid loss additive blend. Patent US 4632186,1986. 

B. G. Brake and J. Chatteiji. Fluid loss reducing additive for cement compositions. Patent EP 595660,1994. 

W. S. Bray and W. R. Wood. Well cementing method using a dispersant and fluid loss intensifier. Patent US 5105885, 1992. 

L. E. Brothers. Method of reducing fluid loss in cement compositions containing substantial salt concentrations. Patent US 4640942, 1987. 

P. S. R. Cheung. Fluid loss additives for cementing compositions. Patent US 5217531, 1993. 

S. C. Crema and C. H. Kucera. Cementing compositions containing a copolymer as a fluid loss control additive. Patent EP 444489, 1991. 

S. C. Crema, C. H. Kucera, G. Konrad, and H. Hartmann. Fluid loss control additives for oil well cementing compositions. Patent US 5025040, 1991. 

K. K. Ganguli. High temperature fluid loss additive for cement slurry and method of cementing. Patent US 5116421,1992. 

D. A. Huddleston, R. K. Gabel, and C. D. Williamson. Method for reducing fluid loss from oilfield cement slurries using vinyl grafted wattle tannin. Patent US 5134215,1992. 

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