A surfactant, or surface active agent, is a molecule that contains both a water loving, hydrophilic part and an oil-loving, hydrophobic part. Because the two parts of the molecule have opposite preferences, a surfactant cannot rest comfortably in a uniform fluid and instead migrates to the interfaces in a system, the boundaries between oil and water, between water and gas, and between fluids and the rock surface. By gathering at these interfaces and lowering the energy associated with them, surfactants change the way an entire fluid system behaves. This single property is the basis of every job a surfactant performs in an oilfield.

In stimulation and production, the most important interfaces are those inside the reservoir. When fracturing fluid, acid, or completion water is pumped into a formation, capillary forces in the small pore throats of tight rock can trap that water and prevent it from flowing back, a condition known as water block. Capillary pressure rises as pore size falls and as the interfacial tension between the trapped water and the surrounding oil rises, so a tight reservoir can take in water and then refuse to release it or to give up its hydrocarbons. A surfactant lowers interfacial tension, which lowers capillary pressure, which allows the well to clean up and produce. Surfactants also prevent emulsions, alter the wettability of the rock, generate stable foam, and disperse organic solids, and the CrudeChem surfactant range is built around these functions.

Surfactants are grouped by the charge on the water loving head. Anionic surfactants carry a negative charge, cationic surfactants a positive charge, nonionic surfactants no net charge, and amphoteric surfactants both charge on one molecule. The charge controls how a surfactant tolerates salt and acid, how it interacts with clay and rock surfaces, and how strongly it adsorbs and is lost from solution. CrudeChem selects the charge type and structure of each surfactant to suit the application, and the products described below, the CSURF surface tension reducers and micelle systems and the CrudeFoam foaming agents, are each matched to a specific duty.

Surfactants are grouped by the charge on the water loving head. Anionic surfactants carry a negative charge, cationic surfactants a positive charge, nonionic surfactants no net charge, and amphoteric surfactants both charge on one molecule. The charge controls how a surfactant tolerates salt and acid, how it interacts with clay and rock surfaces, and how strongly it adsorbs and is lost from solution. CrudeChem selects the charge type and structure of each surfactant to suit the application, and the products described below, the CSURF surface tension reducers and micelle systems and the CrudeFoam foaming agents, are each matched to a specific duty.

The mechanism of CSURF 301 is straightforward interfacial chemistry. The molecule adsorbs at the oil and water interface and at the water and gas interface, replacing the high energy contact between unlike fluids with a lower energy surfactant covered boundary. The measurable result is a reduction in surface tension and interfacial tension. Lower interfacial tension means lower capillary pressure, and lower capillary pressure means the treating fluid penetrates the formation more evenly and load water returns more completely during flowback. When CSURF 301 is used in acidizing, the data sheet describes a second important function: the product disperses oils and sludge so that the acid makes maximum contact with the formation rather than channeling past oil coated rock. CSURF 301 also breaks through water blocks and prevents the formation of crude oil in water emulsions, so the recovered oil and water separate cleanly and flow without the viscosity penalty of an emulsion. The data sheet specifically notes that CSURF 301 can be used as a spearhead fluid in acidizing and fracturing treatments, pumped ahead of the main fluid to lower breakdown pressures and to reduce the chance of forming water and oil or acid and oil emulsions.

In application, the data sheet gives clear treating rates. For acid treatments, CSURF 301 is added into the acid during loading operations at a rate of 1 to 3 gallons per 1,000 gallons of acid. When the product is used in a matrix squeeze procedure, it is mixed with the water, brine, or alcohol carrier at a rate of 1 to 3 gallons per barrel of fluid. The data sheet notes that the correct treating rate varies with the type of treatment, the emulsifying character of the formation oil, the treating fluid, and the volume of solids generated during an acid job, and it recommends field testing to optimize the rate for a given well. CSURF 301 is shipped in DOT approved 55-gallon drums, intermediate bulk containers, and bulk truck transport. Taken together, CSURF 301 is the right surfactant where an operator needs dependable, salt tolerant and acid tolerant surface tension reduction, oil and sludge dispersion, water block relief, and emulsion prevention across a range of completion and stimulation fluids.

CSURF 364 is described as an industry leading advanced micelle solution for use in hydraulic fracturing, a multifunctional additive that performs as both a non-emulsifier and a surface-active agent. It is the flagship surfactant of the CrudeChem range and uses a more sophisticated delivery mechanism than a conventional surface tension reducer. The product works through micelles, which are self-assembled clusters of surfactant molecules. Above a threshold concentration the surfactant molecules organize into tiny structures that turn their oil loving tails inward and present their water loving heads outward, creating an oil compatible compartment suspended in water. The defining feature of CSURF 364 is the size of these micelles. The data sheet states that the micelles are less than 100 microns in size, which allows increased penetration into the tight pore throats of unconventional formations.

Pore throat size is the limiting variable in unconventional reservoirs, where the throats connecting pore bodies are frequently only tens of micron across. A treating fluid built from larger structures cannot enter that pore space, so its surfactant never reaches the oil held in the rock interior. The sub 100-micron micelles of CSURF 364 are dimensioned to pass through these fine throats and carry concentrated surfactant deep into the matrix. The data sheet describes the resulting mechanisms in detail. As a non-emulsifier, CSURF 364 prevents the formation of stable emulsions between the injected fluid and the reservoir hydrocarbons, emulsions that would otherwise reduce flow efficiency and cause blockages. As a flowback aid, it reduces interfacial tension and improves the return of injected fluids from the formation to the wellbore, which restores permeability and improves productivity. Through capillary driven flow enhancement, it adjusts the rock and fluid interactions so that injected fluid penetrates deeper into the matrix, and it assists spontaneous imbibition, the process in which a wetting fluid naturally displaces oil from the rock under capillary forces. CSURF 364 also alters wettability: in water wet rock it makes the surface strongly water wet, and in oil wet rock it shifts the surface toward water wet, in both cases promoting the imbibition of water and the displacement of trapped oil. The data sheet further notes that CSURF 364 contains an additive that inhibits and disperses paraffin in formations where the crude is paraffinic, which is relevant to the Delaware, Permian, Eagle Ford, and Uintah areas where near wellbore paraffin can create blockages.

The benefits stated on the data sheet are specific and measurable. CSURF 364 delivers a reduced surface tension of less than 30 dynes per centimeter, a reduced interfacial tension of less than 3.0 dyne per centimeter, increased production of liquids and a higher return on investment, improved wettability through an altered contact angle, and improved conductivity. The product is applied at a rate of 0.5 to 1.0 gallons per 1,000 gallons of fluid in fracturing applications, and it can be pumped directly into the blender tub or onto the front end of a gel hydration unit, where it also enhances polymer hydration on the surface.

The data sheet also presents Amott cell imbibition testing carried out at 200F and 2,000 psi on Permian outcrop cores from Wolfcamp B, in which the recovery factor of the CSURF 364 treated core rose well above the untreated baseline over the course of the test. The data sheet lists the Permian and Delaware Basin formations in which CSURF 364 has been applied, including the first, second, and third Bone Spring, the Wolfcamp A, B, C, and D, the Dean, Jo Mill, and the upper, middle, and lower Spraberry. CSURF 364 is the CrudeChem product of choice where the objective is to reach and mobilize oil held deep in tight, low permeability rock and to improve fracture cleanup and flowback in unconventional wells.

CSURF 664 is described on its data sheet, like CSURF 364, as an industry leading advanced micelle solution for use in hydraulic fracturing, a multifunctional additive that performs as both a non-emulsifier and a surface active agent, with micelles less than 100 nanometers in size that increase penetration into tight formation pore throats. CSURF 664 shares the advanced micelle delivery platform of CSURF 364, and the two products perform the same core surfactant functions, but CSURF 664 is positioned with particular emphasis on the management of organic deposits and on improving production from wells where paraffinic crude is a concern.

The data sheet describes the working mechanisms of CSURF 664 in full. As a non-emulsifier, the product prevents stable emulsions from forming between the injected fluid and the reservoir hydrocarbons, emulsions that reduce flow efficiency and cause blockages. As a flowback aid, it reduces interfacial tension and improves the return of injected fluid to the wellbore, restoring permeability and well productivity. Through capillary driven flow enhancement, it modifies the rock and fluid interaction so that injected fluid penetrates deeper into the matrix, which is critical in fractured reservoirs where spontaneous imbibition recovers oil from the low permeability matrix. The product improves spontaneous imbibition by altering interfacial tension, wettability, and capillary forces, and it alters wettability in both directions, making water wet rock more strongly water wet and shifting oil wet rock toward water wet, in each case promoting the imbibition of water and the displacement of trapped oil. The feature that distinguishes CSURF 664 is stated directly on the data sheet: the product contains an additive that inhibits and disperses paraffin in formations where the crude is paraffinic in nature. This is especially relevant to the Delaware, Permian, Eagle Ford, and Uintah areas, where paraffin precipitation near the wellbore can create blockages that restrict production. By keeping paraffin inhibited and dispersed, CSURF 664 helps preserve flow in wells that would otherwise lose productivity to wax buildup, which makes it a strong choice for paraffinic plays and for wells where organic deposition is part of the production problem.

The benefits listed on the data sheet for CSURF 664 are the same set of measurable improvements stated for the micelle platform: a reduced surface tension of less than 30 dynes per centimeter, a reduced interfacial tension of less than 1.0 dyne per centimeter, increased production of liquids and a higher return on investment, improved wettability through an altered contact angle, and improved conductivity. The product is applied at a rate of 0.5 to 1.0 gallons per 1,000 gallons of fluid in fracturing applications, and it can be pumped directly into the blender tub or onto the front end of a gel hydration unit for enhanced polymer hydration on the surface. The data sheet lists the same Permian and Delaware Basin target formations as for CSURF 364, including the first, second, and third Bone Spring, Wolfcamp A through D, the Dean, the Jo Mill, and the upper, middle, and lower Spraberry. CSURF 664 gives the operator the deep penetrating, emulsion preventing, wettability altering performance of an advanced micelle surfactant together with built in paraffin inhibition and dispersion, making it well suited to fracturing and production work in paraffinic unconventional plays.

CrudeFoam F-700 is a water-soluble formulation of anionic foaming agents and surfactants, engineered to produce stable foam and to reduce interfacial tension across a wide range of downhole conditions. A foaming surfactant is a specialized class of surface-active agent: rather than suppressing an interface, it deliberately creates and stabilizes one. A foam is a dispersion of gas bubbles in a liquid, and a stable foam exists only because surfactant molecules coat each bubble wall and hold it together against drainage and collapse. CrudeFoam F-700 builds these bubble films and at the same time lowers interfacial tension, which is why the data sheet recommends it for foam fracturing, foam acidizing, acid diverting, water wetting, and the removal of formation fines during well clean out operations.

The mechanism in each of these applications follows from the foaming and surface-active behavior of the product. In foam fracturing and foam acidizing, the foam created by CrudeFoam F-700 acts as a low density, low fluid loss carrier that places proppant or acid while reducing the volume of liquid left in the formation. In acid diverting, the foam preferentially enters and temporarily blocks the most permeable zones, which forces the following acid to treat the less permeable intervals and produces a more uniform treatment. In water wetting and fines removal, the surface-active character of the product helps fluids wet the rock and lift fine solids while cleaning out. The data sheet states that CrudeFoam F-700 is effective in fresh water and in the presence of an influx of hydrocarbons and is thermally stable to 350F, and that it may be used in fresh water, light brine, or acid systems. It is compatible with the anionic gelling agents and friction reducers used in well fracturing operations, which matters because a foaming agent must coexist with the other chemistry in the frac fluid.

The physical properties confirm a water soluble, mildly alkaline anionic foamer. CrudeFoam F-700 is a light-yellow liquid with a specific gravity of 1.0 to 1.1 at 60F, a density of 8.3 to 9.2 pounds per gallon, a pour point of minus 20 to 40F, and a pH of 8.5 to 9.5 measured on a 10 percent solution. It is water soluble, soluble in 15 percent hydrochloric acid, and dispersible in hydrocarbon. The product is applied by either a batch method or a continuous on the fly addition method. Typical treating rates range from 2 to 10 gallons per 1,000 gallons of fluid depending on the fluid being foamed, the treatment type, and the desired foam quality, and when CrudeFoam F-700 is used to emulsify xylene and acid the typical rate is 5 to 10 gallons per 1,000 gallons of treating fluid. The data sheet recommends field testing to optimize the addition rate. CrudeFoam F-700 is shipped in DOT approved 55-gallon drums, intermediate bulk containers, and bulk truck transport.

CrudeFoam F-900 is a highly concentrated water soluble formulation of anionic foaming agents and surfactants, engineered to produce the maximum amount of stable, tight foam together with interfacial tension reduction across a wide range of downhole conditions. It is the concentrated, higher performance member of the CrudeFoam fracturing and acidizing series. It shares the chemistry family and the application set of CrudeFoam F-700, foam fracturing, foam acidizing, acid diverting, water wetting, and the removal of formation fines during clean out, but it is formulated to deliver a stronger, more stable foam at a lower treating rate.

The performance described on the data sheet is specific. Water treated with CrudeFoam F-900 typically produces foam volumes in excess of 80 percent of the liquid volume, and the product forms what the data sheet calls micro compacted foams, which give a highly stable foam with a half life of several hours. Foam half life, the time over which half of the foam drains and collapses, is the practical measure of foam stability, and a half life of several hours indicates a foam robust enough to hold proppant or to divert acid through a long treatment. The mechanism is the same as for the rest of the series: the anionic surfactant adsorbs onto the gas and liquid interface, lowers surface tension so that bubbles form readily, and builds a strong, elastic film on each bubble wall that resists drainage and rupture. The micro compact structure described on the data sheet indicates a fine, tightly packed bubble texture that resists collapse. As with CrudeFoam F-700, the data sheet states that CrudeFoam F-900 is effective in fresh water and in the presence of a hydrocarbon influx, is thermally stable to 350F, may be used in fresh water, light brines, or acid systems, and is compatible with anionic gelling agents and friction reducers.

The physical properties match those of CrudeFoam F-700 closely. CrudeFoam F-900 is a light yellow liquid with a specific gravity of 1.0 to 1.1 at 60F, a density of 8.3 to 9.2 pounds per gallon, a pour point of minus 30 to 40F, and a pH of 8.5 to 9.5 on a 10 percent solution, and it is water soluble, soluble in 15 percent hydrochloric acid, and hydrocarbon dispersible. The key practical difference is in the treatment rate. Because CrudeFoam F-900 is concentrated, the typical treatment rate is 1 to 5 gallons per 1,000 gallons of fluid, roughly half the rate of CrudeFoam F-700, and the rate for emulsifying xylene and acid is likewise 1 to 5 gallons per 1,000 gallons. The product is applied by batch or continuous on the fly addition, field testing is recommended to optimize the rate, and it is shipped in DOT approved 55-gallon drums, intermediate bulk containers, and bulk truck transport. CrudeFoam F-900 is the appropriate choice when an operator wants the strongest, most stable foam from the series and the logistical benefit of a lower treating volume.

CrudeFoam F-1200 is a foaming agent concentrate designed specifically for use in air mist and stable foam drilling, which sets it apart from CrudeFoam F-700 and F-900. Where the lower numbered products in the series are aimed at foam fracturing and foam acidizing, CrudeFoam F-1200 is a drilling foamer, used to create the foam that lifts drilled cuttings out of the hole in underbalanced and air or gas drilling operations. The data sheet states that the product provides high performance foam quality with stability across a wide variety of fluids and field conditions.

Two features make CrudeFoam F-1200 suited to drilling service. The first is salt tolerance. The data sheet recommends the product for use in fresh water, in potassium chloride fluids, and in field brines with chloride concentrations in excess of 150,000 mg/l, which is a very high salinity, and it is the most brine tolerant member of the CrudeFoam series. High salinity tends to destabilize foam, so a drilling foamer that holds up at this chloride level is valuable in areas with saline make up water. The second feature is tolerance to hydrocarbon influx; the data sheet notes that the product exhibits good stability against downhole hydrocarbon influx, which is important because liquid hydrocarbons entering the hole during drilling tend to break foam. The mechanism is the standard foaming mechanism. The anionic surfactant adsorbs at the gas and liquid interface and builds a stable bubble film, but the formulation is built to keep that film intact in salt and in the presence of oil.

The physical properties of CrudeFoam F-1200 differ from the rest of the series in ways consistent with a concentrated drilling product. It is clear to amber liquid with a characteristic odor, a specific gravity of 1.15 to 1.25 at 60F, a typical density of 9.6 to 10.4 pounds per gallon, a flash point of 115F, a freeze point of 10F, and a pH of 8.5 to 9.0 on a 10% solution. The ionic charge is anionic. The product is water soluble, brine soluble, isopropanol soluble, and xylene dispersible. The application rates are stated for drilling. For air mist drilling the typical concentration is 0.1 to 0.5 percent, which is 0.5 to 2 gallons per 10 barrels, and for stable foam drilling the concentration is 0.75 to 2.0 percent, which is 3 to 8 gallons per 10 barrels. The product may be metered into the mist fluid with a chemical pump or poured into the mist tank and mixed with the make up fluid, and it may be used with compressed air, nitrogen, carbon dioxide, or natural gas. CrudeFoam F-1200 is shipped in DOT approved 55-gallon drums and 275 or 330 gallon totes.

The CrudeFoam and CSURF data sheets repeatedly make the same practical point: the correct treating rate and the suitability of a product depend on the specific fluids, the formation oil, and the field conditions, and field testing is recommended to optimize every treatment. No two reservoirs are identical in mineralogy, pore structure, produced water chemistry, crude composition, or temperature, and these differences change which surfactant chemistry, and which treatment rate will perform best. CrudeChem Technology develops and blends surfactant systems to suit specific reservoir and operational conditions, selecting charge type and structure and matching the product to the salinity, the acid system, and the temperature of the target wells, and supporting the recommendation with laboratory testing such as the surface tension, flow rate, and Amott imbibition work shown on the CSURF 364 data sheet.