Fluid Loss Control Additives

A formulation consisting of 2-acrylamido-2-methylpropane sulfonic acid, acrylamide, and itaconic acid has been proposed [676]. Such polymers are used as fluid loss control additives for aqueous drilling fluids and are advantageous when used with lime- or gypsum-based drilling muds containing soluble calcium ions. 

D. F. Bardoliwalla. Fluid loss control additives from AMPS (2-acrylamido-2-methylpropane sulfonic acid) polymers. Patent US 4622373, 1986. 

L. A. Cantu and P. A. Boyd. Laboratory and field evaluation of a combined fluid-loss control additive and gel breaker for fracturing fluids. In Proceedings Volume, pages 7-16. SPE Oilfield Chem Int Symp (Houston, TX, 2/8-2/10), 1989. 

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. 

C. M. Garvey, A. Savoly, and A. L. Resnick. Fluid loss control additives and drilling fluids containing same. Patent US 4741843,1988. 

A. D. Patel. Water-based drilling fluids with high temperature fluid loss control additive. Patent US 5789349, 1998. 

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

T. R. Sifferman, J. M. Swazey, C. B. Skaggs, N. Nguyen, and D. B. Solarek. Fluid loss control additives and subterranean treatment fluids containing the same. Patent WO 9905235,1999. 

J. P. Vijn. Dispersant and fluid loss control additive for well cement. Patent EP 1081112-A, 2001. 

Cantu, L.A. and Boyd, P.A. "Laboratory and Field Evaluation of a Combined Fluid Loss Control Additive and Gel Breaker for Fracturing Fluids," SPE paper 18211, 1988 SPE Annual Technical Conference and Exhibition, Houston, October 2 5. 

Hydrophilic VA-MA copolymers are readily soluble in water, alcohols, acetone, and aqueous alkaline solutions. Unlike styrene-MA copolymers, VA-MA copolymers form few precipitates with salts of heavy metals from aqueous solutions. Titration with sodium methoxide and thymol blue indicator may be used to determine percent anhydride residues. Hydrolysis gives poly(vinyl alcohol-co-maleic acid) copolymer, which can be converted to materials with lactone rings.In addition to being studied as polyelec-trolytes, nonequimolar VA-MA copolymers have been examined and recommended as fluid-loss control additives for drilling needs, soil con-... 

The modification of montmorillonite (MMT) by the nonionic surfactant sorbitan monooleate and the cationic surfactant cetyltrimethyl-ammonium bromide has been examined (30). This compound can be used as a fluid loss control additive for preventing the fluid invasion into a porous pristine formation and avoiding the collapse of borehole wall in nil-drilling excavation. 

The s mthesized organo-clays as a fluid loss control additive performed well in oil phase. The organo-clays modified with 2.0 cation exchange capacity cetyltrimethylammonium bromide and 2.0 cation exchange capacity sorbitan monooleate yielded 100% colloid fraction in colloid fraction tests, showed low filtration loss of 5.7 ml, and left a filter cake approximately 68 /rm thick in American Petroleum Institute filtration tests (31). This indicates that the synthesized organo-clays can be potentially used as fluid loss control additive in oil-drilling excavation (30). 

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. 

A fluid loss additive is described that consists of granular starch composition and fine particulate mica [337]. An application comprises a fracturing fluid containing this additive. A method of fracturing a subterranean formation penetrated by a borehole comprises injecting into the borehole and into contact with the formation, at a rate and pressure sufficient to fracture the formation, a fracturing fluid containing the additive in an amount sufficient to provide fluid loss control. 

Tests showed that a fluid loss additive on a base of a sulfonated tannic-phenolic resin is effective for fluid loss control at high temperature and pressure, and it exhibits good resistance to salt and acid [868]. 

The fluid loss control of aqueous, clay-based drilling mud compositions is enhanced by the addition of a hydrolyzed copolymer of acrylamide and an N-vinylamide [402], The copolymer, which is effective over a broad range of molecular weights, contains at least 5 mole-percent of the N-vinylamide units, which are hydrolyzed to N-vinylamine units. The copolymers can be made from various ratios of N-vinylamide and acrylamide by using common radical-initiated chain growth polymerization techniques. 

Additives that assist the creation of a fracture include viscosifiers, such as polymers and crosslinking agents temperature stabilizers pH control agents and fluid loss control materials. Formation damage is reduced by such additives as gel breakers, biocides, surfactants, clay stabilizers, and gases. 

KiJin, D.A. and Brown, J.L. "Loss Control Additive for Subterranean Fracturing Fluids," US Patent 3,408,296(1968). 

The high level of N2 gas loss severely limits the effectiveness of foamed add fracturing. In an effort to improve fluid-loss control, various techniques and additives have been evaluated. Using foamed brine or a gelled water pad to precede the foamed add was one of the best techniques used to control fluid loss. The nonreadive viscous pad creates fracture extension that allows the add to reach deeper within the fracture... 

The polyacrylate polymers and a derivative of a vinyl acetate maleic anhydride copolymer cause V30 to decrease monotonically with increasing polymer concentration, similar to the CMC polymers (Figure 46). The polymers PVA and poly(vinyl pyridinium) (PVP) hydrochloride markedly increased V30 at low concentration at concentrations above 1 g of polymer per gram of added bentonite PVA functions as a static fluid loss additive. The maximum in the API fluid loss at low PVA concentrations approximately coincides with the maximum in the yield stress and plastic viscosity found by Heath and Tadros (75). The increased static fluid loss is consistent with Heath and Tadros s conclusion that bentonite is flocculated by low concentrations of PVA. The concentration of PVA required to decrease V30 below that of the neat bentonite suspension is significantly larger than the concentration of CMC, where effective static fluid loss control can be achieved at polymer bentonite weight ratios of about 0.1 g/g. More effective fluid loss control has been achieved with other synthetic polymers such as poly(vinyl sulphonate)-poly(vinyl amide) copolymer (40) and other sulphonated polymers (39). 

Mechanisms of Fluid Loss Control. The mechanisms of fluid loss control are not known in detail. The action of additives ranges from straightforward pore bridging-blocking such as bentonite, starch, and asphaltenes to more complex effects with CMC and PAA where the polymeric additives may adsorb on bentonite clay platelets and prevent flocculation by steric and/or electrostatic stabilization. 

Additional large-volume uses of lignosulfonates include animal feed pellet binders, dispersants for gypsum board manufacture, thinners/fluid loss control agents for drilling muds, dispersants/grinding aids for cement manufacture, and in dust control applications, particularly road dust abatement. 

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