Mud additive

Some clay minerals may absorb some of the water contained in the drilling mud. This will cause the clays to swe//and eventually reduce the borehole size to the point where the drill pipe becomes stuck. Prevention mud additives which prevent clay swelling e.g. potassium salt. 

Drilling fluids Drilling glass Drilling mud additives Drillingmuds... 

Although numerous mud additives aid in obtaining the desired drilling fluid properties, water-based muds have three basic components water, reactive soHds, and inert soHds. The water forming the continuous phase may be fresh water, seawater, or salt water. The reactive soHds are composed of commercial clays, incorporated hydratable clays and shales from drilled formations, and polymeric materials, which may be suspended or dissolved in the water phase. SoHds, such as barite and hematite, are chemically inactive in most mud systems. Oil and synthetic muds contain, in addition, an organic Hquid as the continuous phase plus water as the discontinuous phase. 

Alkalinity Control. Water-base drilling fluids are generaHy maintained at an alkaline pH. Most mud additives require a basic environment to function properly and corrosion is reduced at elevated pH. The primary additive for pH control is sodium hydroxide [1310-73-2] in concentrations from 3 to 14kg/m (1—51b/bbl). 

Benzoic acid is also used as a down-hole drilling mud additive where it functions as a temporary plugging agent in subterranean formations. Since this is a secondary oil recovery appHcation, this use is heavily dependent on the price of cmde oil. 

The most common, commercially available drilling mud additives are published annually by World Oil. The listing includes names and description of over 2,000 mud additives. 

Heavy metals are present in drilled formation solids and in naturally occurring materials used as mud additives. The latter include barite, bentonite, lignite, and mica (sometimes used to stop mud losses downhole). There are background levels of heavy metals in trees that carry through into lignosulfonate made from them. 

There are several significant permit conditions. As with all other OCS permits, the discharge of oil-based muds is prohibited. Similarly, the permit does not unconditionally authorize the discharge of any of the eight generic muds. Their discharge is subject to limitations on additives. To monitor the use of mud additives, the permit requires the additive not to drop or to decrease the 96-hr median lethal concentration (LC ) test below 7,400 ppm on the basis of the suspended particulate phase or 740 ppm for the whole mud. This parameter is based on a test of Generic Mud 8, which is formulated with 5% mineral oil. 

There are a variety of chemicals that are toxic and used in the drilling fluid makeup. Chromates and asbestos were once commonly used and are now off the market. A mud inventory should be kept for all drilling additives. Included in the inventory are the material safety data sheets (MSDS) that describe each material s pertinent characteristics. The chemicals found on the MSDS sheet should be compared with the priority pollutants and any material should be eliminated if a match is found. The chemicals should also be checked on arrival for breakage and returned to the vendor if defective packaging is found. All mud additives should be housed in a dry area and properly cared for to prevent waste. Chemicals should always be mixed in packaged proportions. Wasted chemicals, ejected to the reserve pit by untrained personnel, can present future liabilities to the operator. 

Uintaite is not easily water wet with most surfactants. Thus, stable dispersions of uintaite are often difficult to achieve, particularly in the presence of salts, calcium, solids and other drilling fluid contaminants and/or in the presence of diesel oil. The uintaite must be readily dispersible and must remain water wet otherwise it will coalesce and be separated from the drilling fluid, along with cuttings at the shale shaker or in the circulating pits. Surfactants and emulsifiers are often used with uintaite drilling mud additives. 

K. Christensen, N. Davis, II, and M. Nuzzolo. Water-wettable drilling mud additives containing uintaite. Patent EP 460067, 1991. 

The data from these first two batch tests indicated that poly(lignin-g-(l- amidoethylene)) hag properties which make it a potentially effective drilling mud additive. The tests show that poly(lignin-g-(l-amidoethylene)) and its hydrolyzed derivatives act as a high temperature thinner and as a filtrate control agent. The... 

Amanullah Md. (2007) Screening and evaluation of some environment friendly mud additives to use in water based drilling muds. SPE-98054 SPE Environmental and Safety Conference,... 

The most widely used synthetic and natural enhanced oil recovery polymers, such as partially hydrolyzed polyacrylamide, carboxymethyl(ethyl) cellulose, polysaccharides, or xanthan gums, are not suitable for high-temperature reservoirs (> 90 °C) with high-density brine fluid due to excessive hydrolysis and precipitation [277]. The main advantages of polymeric betaines over the mentioned standard polymers are (1) thermostability (up to 120 °C) (2) brine compatibility and (3) viscosification in brine solution [278]. Carbobetaines grafted onto hydroxyethyl cellulose were tested as a drilling-mud additive for clay hydration inhibition and mud rheological control [279]. An increase in the content of carbobetaine moieties resulted in an enhanced inhibitive abiUty, especially for sahne mud. 

Carboxylmethyl cellulose (O Scheme 1) is produced in many grades by many manufacturers owing to its various end use applications as well as simple reaction protocol. CMC is used in detergents, paper coatings, drilling mud additives in oil well drilling, cosmetics and pharmaceuticals (as fat free ointments for example) and in food products (soups, ketchups, etc.). 

Cydril [Cytec]. TM for a drilling mud additive, shale stabilizer and viscofier. 

Use Dispersing agent in concrete and carbon black-rubber mixes, extender for tanning agents, oil-well drilling mud additives, ore flotation agents, production of vanillin, industrial cleaners, gypsum slurried, dyestuffs, pesticide formulations. Commercially available as the salts of most metals and of ammonium. 

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