DE2451773C3 - Spacer Fluid for Keeping Two Well Fluids Separate and its Use - Google Patents

Description

The invention relates to a spacer fluid for keeping two borehole fluids separate from one Water-in-oil emulsion with about 40 to 60 percent by volume a hydrocarbon oil and about 60 to 40 percent by volume water, an emulsifier with a Fatty acid component and a surfactant dispersant, as well as the use of such Spacer fluids for keeping drilling mud and a cementing composition separate.

When cementing casing pipes and liner feet in a borehole there are oil and gas producing Industry for many years problems with no optimal solution. In general, after the Completion of the drilling of a borehole, the drilling mud used is displaced by the cement that used to cement the casing. The compositions and properties of Drilling muds and cements have been varied widely with the result that interfacial contact often strong between the displacing cement and an incompatible drilling fluid disruptive physical and chemical interactions which are the cause of numerous of the the problems that occurred.

If z. B. a drilling fluid with high viscosity and high density is used, the described Incompatibility lead to a satisfactory bond between the cement and the Borehole is not reached If a water-based drilling fluid is used, one is sufficient Difficulty removing the mud and mud cake from the borehole. When drilling fluids oil-based (invert drilling fluids) are used, the incompatibility often results in contamination or mixing the mud with the cement and the cement with the mud. Extreme viscosities of the sludge are often the result of such mixing together, causing fluctuations Pressures and pumping problems. In some cases this leads to an undesirable one

3 4

Collapse of the formation. When the hold on when drilling oil and gas wells

substances mixed with the cement can be used. So are the inventive

There is often premature hardening of the cement spacer fluids with water-based mud systems

induced, and if, conversely, the Bohrfiuide with ferrochrome lignosulfonate type and poly-

the solids from the cement slurry are types compatible, and they are also compatible with

are contaminated, the advantageous properties of oil-based foam systems are compatible, namely

ten of Bohrfiuide adversely affected. So can in all weight ranges in which such systems

z. B. Invert emulsion type drilling fluids (to be commonly applied. In other words

Oil base) to break down the emulsion, this means that the slurry according to the invention

brought about, resulting in higher viscosities and io mungen with practically all oil-in-water emulsions

higher pump capacities are required. as well as with all water-in-oil emulsions

Because of the difficulties described, which are with Hch. The spacer fluids according to the invention are a direct displacement of Bohrfiuide with cement compatible with the types of cement, which are common when using drilling muds and wise when cementing Ölbohilöchem oil drilling cements are used at the end and cementing 15, and they increase their viscosities of a borehole, often occur The required pumping times were not preceded or changed in such a way that a separation of these two would not be involved Invention or separating fluid was given Numerous slurries according to the invention as spacer fluid between two different types of spacer fluids, cement and drilling muds were also made, also those already used, and in some cases between two Several types of spacing fluids can be used in one of the many drilling muds used in the event that one is to be displaced by the other single system for displacement operation. Applied to the invention. This requires a considerable amount of fluids, up to any desired density, of expensive equipment and specialized personnel over a wide range in specific gravity. Various types of oil-like materials can be raised and easily made up for spacing liquids or fluids to have a density between that between cement-based slurries and the density of the drilling fluid and the density of the oil-cement-based slurries. Such spacer oils allow sludge in the system in which the spacer does not allow the cement to adequately hydrate, fluidly operate,
and the oil thins the mud. In addition, the spacing fluids according to the invention cannot distinguish the oil that maintains the spacing with a characteristic in that the water content of the water in the specific gravity of the water produced in-oil emulsion is fresh water which has a content in order to increase the density of the sludge. 35 dissolved chloride salts of less than 1000 ppm lead to an effective removal thereof and achieve a total hardness of less than 500 ppm. In addition, the impossibility of showing that the emulsifier produces about 1 to 20 weight percent of any of the oil-type spacer fluids with 100 percent of a fatty acid amide with about 16 to sufficiently high specific gravity brings about 22 carbon atoms and about 55 to 78 weight percent hydrostatic imbalance Column in the 40 of a solid, particulate support material from the annulus of the borehole with it. Generally comprises lime or diatomaceous earth, on the top of which it is desirable and advantageous to have a spacer surface the fatty acid amide is adsorbed and that the fluid slightly heavier than the sludge, a sulfonated surfactant dispersant which it displaces, and one Cement slurry that is paraffin, resin acid, a resin soap and / or a slightly heavier than the spacing fluid. This is 45 a mixture of a sulfonated lignin with an oleyl but is very difficult with many types of amide.
to achieve stationary fluids that have been used so far. The following is more detailed

From US-PS 28 05 722 and 36 25 286 are already descriptions of the various components of the invention spacing fluids for keeping two wellbore spacing fluids or spacing liquids apart in the form of water-in-oil emulsions 50 and the manner in which such fluids are given with approximately equal proportions of oil and water known, preferably be made up, the in the in which a hydrocarbon oil, an emulsifier abstinence fluid, the water used is fresh water. and a surfactant dispersant. This term is used in contrast to water and wherein according to US-PS 36 25 286 applies, which has a high content of dissolved, anorzzo with the emulsifier a fatty acid compound and especially a considerable one nent is used. Contains chloride salt content. According to the invention

The object of the invention is a universally applicable fresh water that can be used as water Barable spacing fluid, which can be defined for any drilling fluid, the one dissolved entity and without significant change in the rheochloride salt content of less than about 1000 ppm and logical properties of the drilling mud or the 60 have a total hardness of less than 500 ppm (ppm = parts Cement and without changing the for the use per million) contains.

the cement slurries required pump- The used in the manufacture of the emulsion «

times can be used. oil is a hydrocarbon oil that is suitably «

The spacing fluids according to the invention are practically diesel oil, crude oil, kerosene or one of the several different ones

universally applicable, have excellent 65 other hydrocarbons or a mixture

Temperature and pressure stability and are effective in hydrocarbons. You provide diesel oil

Cement slurries are also currently the preferred oil component.

The oil and fresh water are separated from practically all sludge systems in the

Spacer fluids according to the invention in volume-emulsifying coniponeates in the proportions according to the invention of about 40-160 to about 60:40 oil to form compositions, and preferably water is used. It is preferably derived from the reaction of 12 to 18 carbon parts by volume to about 55 parts by volume oil with about 55 material atoms containing fatty acid with an amine. About 45 parts by volume of water 'combined. In general, the amide reaction product will preferably contain, in the most advantageous composition, from about 16 to about 22 carbon atoms and 1 to 2 of the spacer fluid for most applications. Most preferred, single approximately equal parts by volume of water and oil. In any oleyl amide, the product that is produced by condensing the spacing liquid or the spacing fluid of oleic acid with diethanulamine is a relatively weak (balanced) water-in-oil io that is the main component of the in an invention emulsion (invert emulsion) . In other words, with the emulsifier used in the spacing fluid, this indicates that the oleylamide, which creates the interfacial tension forces, serves to balance the interfaces in the emulsion so that the emulsion tension between the oil and the water, which can easily overturn, becomes an oil-in-water emulsion the main components of the spacer fluid emulsions can be reduced to represent compatibility with a 15, so that if the water-based mud mix is maintained, agitated, or agitated, it is easily employed alongside such drilling muds. Water-in-oil emulsion is prepared, and thus the "balance" of the spacer fluid emulsions their stability for sufficient periods of time according to the invention is an essential factor in order to be maintained. If less than about 1% of their compatibility with virtually all drilling muds is used, 20 weight percent of the oleylamide will allow and cement slurries currently in use will not allow sufficient degradation. surface tension is maintained, and it is difficult to obtain a

If the amount of used in the spacer fluid is complete emulsification of the spacer fluids together

detem oil to achieve a volume ratio to water of about settlement. The addition of 20 weight

1.5: 1, it has been found that the 25 percent of the total weight of the emulsifier exceeds

Standing fluid adjacent cement produces undesirable incremental amounts of oleylamide, except that

Experience a reduction in the setting time. If this is uneconomical, excessive dispersion

Ratio falls below about 1: 1.5, the capacity of the inner water phase in the continuous oil

ability to maintain the continuity of the oil phase of the emulsion.

phase lost, and the fluid or the liquid 30 in addition to the oleylamide contained in the becomes an oil-in-water emulsion. The ability to use spacer fluids of the invention emul change the oil-to-water ratio within gators, preferably also dimerized oleic acid, the specified range enables greater adsorbed on the particulate support material, Flexibility to selectively adjust viscosity, in an amount up to about 30% by weight the weight of the spacer fluid. In this 35 percent of the total weight of the emulsifier is present. It should be noted that the term "weight" used in the specification is preferably from about 5 to 15 weight notation, if it is used as a percentage. The dimerized oleic acid acts does not refer to percentages or parts by weight if used to increase viscosity refers, as a term of this technical field, to the spacing fluid whereby it is possible to use it actually refers to a density parameter, a variety of conventional 4 used the density is, where it is usually given in kg / 1 to increase materials in weight, e.g. B. will. with barium sulfate, calcium carbonate, iron oxides,

The lead sulfides and cement solids contained in the spacer fluid according to the invention, so that a The emulsifiers used consist in principle or selective adjustment of the weight (density) of the essentially from an oleylamide, which is possible on a 45 spacing fluid over a wide range particulate, solid support material in the form of. If concentrations are greater than about 30 GeKalk or diatomaceous earth, or mixtures thereof, weight percent dimerized acid absorbed in the emul is. The gator used in the description is used as the spacer fluid in Term "lime" includes: calcium oxide, calcium - undesirably thick, and its viscosity increased hydroxide, magnesium oxide or mixtures of these 50 reduce the pump performance to an undesirable level. Links. Also includes that in the description for most applications of in their weight Exercise used the term "emulator" both that (density) increased spacer fluids has a lot solid, particulate carrier material as well as that of about 10 percent by weight as optimally particulate Materials that puts on the surface.

of which are adsorbed, although only one or a few 55 It should be noted that in the case of application

of the latter materials al. «Emulsifier per se place at a relatively low temperature and in cases

can work. where very little or no weight (density)

The oleyl amide used in the emulsifier is added to the spacer fluid as enhancing material

on the surface of the particulate carrier, the dimerized oleic acid from the emulsifier

terials absorbed in an amount that can be omitted from about 1 to 60 composition. This

however, about 20 percent by weight based on the total cases are relatively rare and in most cases

By weight of Emu! cases used in the spacer fluid, the dimerized acid is preferred

gator, varies. Preferably from about 2 to are used.

about 10 percent by weight oleylamide is used, of minor importance for addition to the

the most advantageous amount of this compound contained in the emulsifier used in the spacing according to the invention

The most frequently used emulsifier, such as fluids, is the addition of oleic acid,

4.9 percent by weight. however, this takes some precedence over the spacing fluids

The oleylamide described here is believed to be able to impart desired properties. When olein-

7 8

acid is used, it becomes in a range of problems in the practice of the invention

is about 3 to about 15 weight percent of the total spacing fluids. Suitable asphalt resins include

weight of the emulsifier applied. Preferably those which have a melting point between 121 and will have from about 3 to about 10 percent by weight of 204 ^° C. Boiler residues, lu't-

Oleic acid used. Most beneficial amount of 5 blown resins or naturally occurring resins

is about 5 percent by weight. Be the addition of this. If such asphalt resins are used,

Material supports the stabilization of the spacing- can be as small as about 55 weight-

fluid emulsion can be used against breaking at the percentage of lime carriers,

tact with salt-containing, underground waters in addition to that in the invention and how

and especially in the case of fossil waters with a high IO previously specified composite spacer fluid

Salinity. entered emulsifier can be the spacer fluid

It is also a very useful additive and a highly surfactant dispersion when the cement used contains substantial amounts of material. This component of the distance from Contains sodium chloride. fluid composition serves to reduce the particle transport

It should be noted that when oily, solid, weight (density) increasing acid is added to the emulsifier composition, it is economical to disperse materials in the spacer fluid, if used, considerations often the use of not, and further It is used for distilled, dark oleic acid (oleic acid) in a mixture. It prevents solid constituents, which are in the red oil obtained with impure oleic acid (red oil) from either the drilling mud or instead of pure oleic acid. The not destil- ao the cement sludge, between which there is gelled, dark oleic acid containing about 75 % oleic acid, could enter, break the emulsion and affect smaller amounts of linoleic acid, linolenic acid, or detrimentally. A variety of borderline palmitoleic acid, palmitic acid, myristic acid, myristic acid dispersants can be used, ristoleic acid and stearic acid. The impure oleic acid (red oil) obtained from being, including from sulfonated paraffins, olein of such non-resin acids and resin soaps (e.g. the disproportionately distilled, dark oleic acid mixture is the re-ned resin soaps, which stood out during the distillation of, The boiler residues formed in a conventional destination tall oil originate from the process of oleic acid, and it contains the soaps and soaps of such acids) as well as mixtures of oleic acid described as well as amounts of the other acids described by sulfonated lignin with certain, particulate acids mentioned above, including small amounts 30 shaped oleylamides, which are still in the dimerized acids in the foleiniger. the manner described in the emul-

An emulsifier that distinguishes itself as being particularly effective in the case of oleylamides contained in gator. Such The spacing fluids according to the invention are exposed to dispersants in the spacing fluid in consists of powdered, gray-white, slaked in an amount of about 0.00142 to about 0.0286 kg per Lime, which is entered in the emulsifier composition in a 35 liter. Preferably the amount is Amount ranging from about 55 to about 78 weight surfactant dispersant used percent is present and the other components from about 0.00572 to about 0.0228 kg per liter. When of the emulsifier adsorbed on its surface - the most preferred, which is still retained in the following: Oleylamide, derived from the condensation, surface-active dispersant vervon oleic acid is used with diethanolamine, in an amount in the 40 range, is that in the spacing fluid range from about 3 to about 10 weight percent, most advantageously applied amount about 0.0114 kg as well as dimerized oleic acid, in an amount im per liter.

Range from about 8 to about 12 percent by weight. The preferred surfactant dispersion

is present. compositions are those obtained by mixing

The most preferred single emulsifier of a sulfonated lignin, such as waste sulfite liquor, Composition for use in invention with an oleyl amide, which results from the reaction of a moderate spacing fluids consists essentially of oleyl chloride with a 2 to 5 carbon atoms depowdered, slaked lime derived in an amount from containing aminosulfonic acid, formed about 68.1 percent by weight, about 4.9 percent by weight. A surfactant dispersant, Oleylamide, not distilled oleic acid, which is found in a 50 which is particularly advantageous and highly effective amount of about 5 weight percent is present in the spacer fluid compositions out of more impure, Oleic acid (red oil) derived from olein, which has provided and which is the preferred dispersion an amount of about 5 percent by weight is an agent for use according to the invention, as well as undistilled, dimerized oleic acid, which is a product made by the reaction of oleyl chloride present in an amount of about 10 percent by weight with n-methyl taunn and then blending this is. Reaction product, which is an oleyiamide, with

In order for some applications of the spacer fluids to have waste sulphite liquor in an amount in the range of 25 of these spacer fluids a fluid loss control at percent by weight to about 75 percent by weight of the sulphite part, it is sometimes advantageous to make something into the leaching oil amide! In addition to the emulsifier 60 described, the oleylamide reaction is most advantageous to add conventional, particulate, solid, asphalt and the sulphide solution in practically equal amounts of resin, which is mixed with the resulting mixture Amount in the range of formation of a solid, particulate composition about 1 to about 20 weight percent based on the composition spray dried. The weight of the emulsifier in the description is added. 65 used the expression "Abfalisülfitlauge" Iraicihnejt ^ et ^ fr *> Erw "be deliver from about 10 to about 14 weight waste lye, y ^^ e '^ i ^ ihsi ^ orate' ^ ih ^ aa ^ cl ^ percent of an asphalt resin adequate fluid verYipstkonfrolle b ^ were gebndet the Sulntpapier-Herstellüngsprozeß the rare cases where this or force-Lig & ini !, difj sulfoniertwinden. ,, IJ ^^,

¥ 559

Z4Ö1

In addition to the function of dispersing and supporting the suspension of solid particles which are in the spacing fluid from the adjacent cement slurry or could enter from the drilling mud removed therefrom, enables the surfactant used in the spacer fluid Dispersants the rapid dispersion of conventional, the weight (density) increasing Materials such as particulate !, solid Qzarz, calcite, barite, iron oxide, etc. in the spacer fluid representing water-iri-oil emulsion.

It has been found that the constituents described (emulsifier and surface-active dispersant) containing spacer fluids are capable of weight (density) increasing materials disperse or suspend in an amount sufficient to provide a weight to the spacer fluid (a density) of 0.96 to 2.39 kg / l.

When preparing the spacer fluid emulsion according to the invention, the emulsifier material becomes too first added to the oil. A fluid loss additive such as the aforementioned asphalt resins can simultaneously or added later if used. After the solid emulsifier and fluid loss additive materials, if present, have been added to the hydrocarbon oil, the solids in the oil are thoroughly dispersed, and then the fresh water is added to the slurry to form a water-in-oil emulsion. After the emulsion is formed, the amount of surfactant specified above becomes Dispersion material is added to the spacing fluid with the addition of any density enhancing materials that are used to complete.

The spacer fluids produced in this way are generally weaker emulsions than the drilling fluids, which are intended to keep them away from the various cement compositions. Since the spacer fluid, although a water-in-oil emulsion, is balanced or in equilibrium through the use of approximately equal amounts of dispersed and continuous phases, the emulsion can be converted to an oil-in-water emulsion if it contains an excess amount of water. In other words, in the case of using a water-based drilling mud, water from the drilling mud has a tendency to increase the water phase in the spacer fluid, thereby reversing it and becoming an oil-in-water emulsion. In this way it maintains its compatibility with the mud as well as with the cement. The use of the strong, surfactant dispersion material in the spacer fluid enables it to be adjusted in density over a wide range of from about 0.96 to about 2.39 kg / l as desired, this material also serving to serve any Wet cement solids that could migrate from the neighboring cement slurry in the spacing area with ΟΓ. In ascend '' are the distance fluids with all types of Zementaufschlämmtingen, ^ste1uOng: Yerwendfei are ΪVerträglich, and they do not increase the viscosity and do not change the pumping times of such cement slurries.

When used, the inventive Spacer fluid is pumped into a completed borehole behind the drilling mud to remove the mud flush out the borehole, and it is moved in front of the cement column, which into the borehole for Is pumped in for cementing purposes. In general it is preferred to bring the spacer fluid in weight to a density which is somewhat heavier than the density of the drilling mud it moves, and slightly lighter than the cement mud, which follows the spacer fluid.

ίο The invention is based on the following examples explained in more detail, the spacer fluid compositions according to the invention and the function certain components thereof are explained in more detail. In all examples, the data relate on the preferred surfactant dispersant to a mixture of equal parts of waste sulphite liquor and oleyl amide resulting from the reaction of oleyl chloride with n-methyl taurine.

B e i s ρ i e 1 1

A borehole was drilled to a depth of 6400 m at a location in California, with a circulation temperature at the bottom of the borehole of 154 ^° C. being given. When completing the drilling

* 5 holes became the one used when drilling the hole Mud through the annulus between the casing and the wellbore using a spacer fluid displaced, which between the mud and the the spacing fluid for the purpose of cementation

cement slurry following the piping. The sludge used had a density of 2.15 kg / l and was a sludge based on water containing lignosulfonate. The cement used was an API Class G cement with a density of 1.72 kg / l, and he wa, by adding small amounts modified by sodium chloride, silica flour, iron oxide and a suitable retarder.

The spacing fluid prepared according to the invention, which is used between the cement and the mud had a weight of 2.18 kg / l, which was obtained by using barium sulfate as the density increasing material was achieved. The spacer fluid emulsion contained water and oil in a 50:50 volume ratio and contained 0.0711 kg of an emulsifier per liter, which is 68.1 percent by weight contained powdered, slaked lime adsorbed on its surface: 4.9 percent by weight oleylamide, resulting from the condensation of oleic acid with diethanolamine, 5 percent by weight not distilled

oleic acid, 5 percent by weight impure, from oleic oleic acid obtained (red oil) and 10 percent by weight of undistilled, dimerized oleic acid. The spacing fluid also contained 0.0114 kg of the borderline fluid preferably used in the spacer fluids of the invention

surface-active dispersant per liter. SchheßÜcif the spacer fluid used contained 12 percent by weight of an asphalt resin used for reduction was added by fluid losses. ^ '1

The mud and cement that came with the note '-

If this experiment were to be used in California, they are not compatible with one another. 795Ö1 i ^ i * - standing fluid was established between Schlamni and Zsment; used. "■ '■"} ■' ■ - '■■' ■■■■ '■ * - ^; '^; ^ - '- ^ Vk-S

The critical speeds at which Üer'l

Transition from laminar to turMl ^ tbr Stiörmmg "~

occurs, were measured and 1ur den; iföhrsctiiamk S

au 'J ¹ V Atekndsaüid allejne, a Gemschleifs

Spacing fluids and the cement used; as well as "■

45

V -S ^ iTi

¥

hu "\ V ..- J - i

a mixture of the spacing fluid and the drilling mud estimated. The temperature at which the critical speed tests are carried out was 93.3 ° C. The critical speeds were determined for different sizes of the

The circular ring determines how it is determined by the difference between the diameter of the ear hole and the outer diameter the piping is determined. The results of these tests are given in Table I below compiled.

Table I.

Critical speed ( m / min), related 50.8 76.2 on the borehole diameter minus the external 127.0 152.4 Piping diameter (mm) 25.4 112.8 97.5 101.6 82.3 76.2 Drilling mud 143.3 70.1 53.3 88.4 38.1 35.1 Spacer fluid 108.2 73.2 62.5 44.2 50.3 45.7 Spacer fluid + 50% cement 99.1 54.7 Spacer fluid + 50% mud

103.6

76.2

64.0

56.4

51.8

47.2

The results of the measurements of the critical speed show that much lower critical Speeds for mixtures of spacer fluid with either cement or mud than in the case of the mud alone. There is therefore no harmful increase in viscosity, and greater ease in achieving turbulent flow is noted, if so substantial mixing of spacer fluid with either the mud or cement occurs.

Example 2

There were preliminary tests before the completion of a Well completed in east Texas. The borehole was 2957 meters deep and had a circulating temperature at the base of 121 ° C. The mud used to drill the hole was an oil-based mud with a density of 1.675 kg / l, and the API grade Η cement used to complete the wellbore had a density of 1.89 kg / l. The cement contained 18% sodium chloride, a small amount of a commercially available friction reducing agent and a small amount of retarder.

The spacing fluid, which was composed as indicated in Example 1, but using Barium sulfate was brought up to a weight of 1.675 kg / l, was placed between the mud and cement selected To determine the influences on viscosity, their occurrence as a result of some occurring at the interface between the spacer fluid and the sludge Contamination could be expected, as well as between the spacing fluid and the cement, various examinations were carried out with a Fann viscometer, and the results of these Investigations are compiled in Table II below.

Table II

Contamination studies 600/300 Fann reading

Volume percent contamination 0 10

30th

50

Mud + cement
Mud + spacer fluid
Cement + spacing fluid

3O0 + / 30O + 300 + / 276 300 + / 260 300 + 7210 63/30 59/33

3OO + / 3OO + 300 + / 300 + 3OO + / 3OO + 3OO + / 3OO +
295/177 257/152 202/133 204/118
62/37 61/38 58/38 56/36

The results shown in Table II show that the Fann tests for type of mixing developed viscosities, which are likely at the interface between spacer fluids and mud can occur much less are than those without using the spacer fluid at the interface between sludge and cement could occur. The same is true for those at the interface between spacer fluid and cement developed viscosities, with varying levels of impurities up to a 50:50 volume ratio of contamination were assumed.

Example 3

For the purpose of completing a borehole drilled in Oklahoma to a depth of 6096 n ^ das a circulation temperature of. 149 ° C at the bottom of the borehole, a spacer fluid, which as in Example 1 described was composed according to the invention set to it between a drilling mud water-based and ferrochrome lignosulfonate with a density of 1.28 kg / 1 and one To arrange cement with a density of 1.53 jkg / l. The spacer fluid was brought to a density of 1.38 kg / l with barium sulfate. Investigations using

¥

Fann viscometers as described in Example 2 were then run to determine the effects to examine the viscosity of the system of intermingling or bringing together that at the interfaces of the spacer fluid with the

(J

Cement or mud, compared to the viscosity effect resulting from mixing the Sludge with the cement occurred when the spacer fluid was not used. The results are in the Table III compiled.

Table IH

Contamination tests 600/300 Fann reading

Volume percent contamination 30th

40

50

Mud + cement
Mud + spacer fluid cement + spacer fluid

133/82 156/94 182/109 230/135 97/58 97/58 105/60 105/60 33/22 32/20 27/17 26/17

Example 4

A borehole of 5486 m with a circulation temperature of 139 ° C at the bottom of the borehole, which was in Louisiana using an oil-based drilling mud at a density of 2.10 kg / l was to be finished with an API class Η cement with a density of 2.17 kg / l. This Cement contains an iron oxide as a density increasing agent, silica flour and a small amount of one commercially available retarder. A spacing fluid was made to keep it between between the cement and the mud, which had a weight of 2.01 kg / l, which was through Increasing the density was achieved by means of barium sulfate. The spacing fluid also had the composition of the spacing fluid specified in Example 1. There were investigations in the Fann viscometer performed on the spacer fluid in admixture with both the mud and cement, and the results were compared to measurements of Fann viscosity taken on various Mixtures of cement and mud were carried out. The results are in the following Table IV compiled.

Table IV

Contamination 600/300 Fann reading

Volume percent contamination 0 10

30th

50

Cement + mud 3OO + / 21 293/170

Mud + Absitandsfluid 129/73 98/58

Cement + spacer fluid 224/132 194/116

300 + / 250 300 + / 243 300 + / 276 3O0 + / 30O + 94/55 90/51 84/48 81/45

116/105 155/100 137/83 157/93

Example 5

Four spacer fluid compositions were prepared, each 108 ml No. 2 diesel oil and one contained an equal volume of water. Each composition further contained 0.0428 kg per oleic acid Liter 0.00428 kg oleylamide (condensation product of oleic acid and diethanolamine) per liter 0.00428 kg dimerized oleic acid per liter and 1.50 kg of barium sulfate per liter as the density increasing material. The amounts and types of solid support in the emulsifier composition was varied in the four batches, as was the amount of surfactant Dispersant. These changes in composition were as follows:

Composition A: 0 ^) 570 kg / 1 calcium oxide and 0.0114 kg / 1 of the preferred, surfactant dispersants described above.

Composition B: _e

iXeseibe composition with A, but without Inclusion of lime or your other solid support

Composition C:

Same composition as B except that 0.0143 kg / l of the preferred dispersant / surfactant Means were used.

Composition D:

The same composition as A except that it contains 0.00572 kg / l sodium hydroxide Place of calcium hydroxide were used.

To estimate the viscosities and the intrinsic; To determine the stress collapse forces of the spacer fluid compositions, stress collapse studies were performed in the Fann's viscometer on compositions A, B, and C. Composition D did not form an emulsion, L ₁ indicating that NatiiHmhydroJad H »c ! itL an LSteÖe φ ^ calcium hydroxide used as carrier material / wenieiiv can. The results of the studies' viscosity and breakdown below. Voltage «are in the following table V together.

15th

TabeUe \

Composition AB C

Apparent viscosity 600 Fann reading, 300 Fann reading Plastic Viscosity Yield Point, 200 Fann reading 100 Fann reading 6 Fann reading 3-Fann reading Collapse under tension

The results given in Table V show that the elimination of the solid support (CaOH) at

95 150+ 150 + 190 300+ 300+ 140 300+ 244 50 90 118 286 207 86 227 163 31 93 69 27 49 39 70 74 34

the spacer fluid (composition B) gives too high a viscosity than that the spacer fluid still would be useful. The addition of 25% more surfactant / dispersant to the composition C does not adequately decrease viscosity to solve this problem.

Example 6

Various of the ingredients were added to a mixture of 108 ml of No. 2 diesel oil and 108 ml of fresh water the spacer fluid composition set according to the initiation, with the exception of the oleyl amide of the emulsifier. Eight compositions were formulated in this way, and their properties des is collapse under tension were then definitely. Table VI shows the composition of the various batches and the results achieved with them Collapse under tension indicated.

Table VI

component

Composition (g / l) 1 2 3

5 »)

6 ·)

Dimerized oleic acid 7.11 7.11 7.11 7.11 4.28 4.28 10.0 7.11 Asphalt materials - 11.45 11.45 11.45 5.72 5.72 5.72 - Dispersant / surfactant
medium - - 11.45 11.45 2.83 14.3 14.3 22.8 Barite - 1497 1497 ,. Collapse under tension **) 20th 12th 50 16 0

*) The solid components were put all together in the diesel oil, which was then added to the fresh water. **) Compositions 4 and 7 are too thick to accept and mix with all of the barite. In the case of Composition 8, the emulsion broke during the addition of the barite.

The poor results obtained in the case where the emulsifying agent oleylamide, which is im Emulsifier was used and the solid support (lime, etc.) omitted show the importance the addition of these components.

Example 7

A number of compositions were prepared, each of which was 151 ml No. 2 diesel oil, 151 ml fresh water and 0.313 kg of barite with a specific gravity of 4.23 per liter. The others Components of the compositions were varied in the following way:

component

Composition (g / l) 1 2 3

Oleylamide *) Dimerized oleic acid oleic acid Friction reducing agent * *)

4.28 - -

- 7.11 -

- - 7.11

*) Reaction product of oleic acid and diethanolamine. * ·) Derivative of dodccylbenzenesulfonic acid.

4.28 4.28 - 4.28 4.28 7.11 - 7.11 7.11 7.11 - 7.11 7.11 7.11 7.11 - - - - 5.72 609 649/359

17 ¹⁸

The studies in the Fann viscometer and the collapse under tension were as before described, performed on the eight compositions. The results obtained are m the following « Table VII compiled. '

Table VI composition 2 3 53 4th 5 6th 80 7th 8th 1 174 27 175 58 50 83 77 40 165 26th 142 31 30th 59 57 600 reading 21 9 1 33 27 20th 24 20th 300 reading · .. '. 19th 156 32 109 4th 38 35 37 Plastic viscosity 2 158 23 122 27 25th 48 47 Yield point 15th 137 7th 96 14th 8th 35 35 200 reading 10 24 5 37 3 5 13th 12th 100 reading 3 18th 100 32 2 100 10 8th 6 reading 2 100 60 62 60 20th 3 reading 72 Collapse under tension

The values in Table VII show the need

the addition of the dimerized oleic acid in the example
composition to ensure adequate capacity by the 30th

Wearing the weight-increasing substances to obtain 0.0286 kg of CaO per liter were given to each of the eight

(Breaking point of at least 8), but compositions as in Example 7 are still given

showed that the dimerized acid was added when only added. The investigations

application or in a relatively high concentration to the viscosity and the breakdown under

The viscosity of the composition tends to be a 35 tension of the compositions so modified

to increase higher than the optimal value. showed the following results:

Table VIII composition 2 3 4th 5 6th 7th 8th 1 115 64 145 60 100 80 92 42 82 37 114 35 70 55 67 600 reading 22nd 33 27 31 25th 30th 25th 25th 300 reading 20th 49 10 83 10 40 30th 42 Plastic viscosity 2 72 27 95 25th 60 45 55 Bk-uch point (yield point) 15th 64 15th 75 17th 52 22nd 40 200 reading 9 11th 4th 30th 5 14th 11th 14th 100 reading 3 7th 3 24 4th 7th 9 11th 6 reading 2 80 0 66 60 52 60 40 3 reading 2.8 Collapse under tension

The properties of the abstinence fluid emulsions, 60 No. 2 and fresh water contained, and each 0.0114 kg which are shown by these values are generally per liter of the preferred surfactant dispermein by adding the particulate calcium ionizing agent (a mixture of equal parts of waste oxide improved. sulphite liquor and that derived from methycaurine

Oleylamide). The remaining components of the

B e i s ρ i e 1 9 65 different compositions were as in

Table IX shown varies, which also shows the density

Nine spacer fluid compositions were reported in kg / l of each of the spacer fluids obtained produced, each of which is equal volumes of diesel oil.

153 121 102 153 121 102 42 42 42 0.314 1.069 1.534 1.15 1.72 2.07

19th

Table IX

composition

1 2 3 4 S 6

Diesel No. 2, ml 153 121 102 153 121 102

Fresh water, ml 153 121 102 153 121 102

Emulsifier, g / l *) 71 71 71 57 57 57

Barite, kg / 1 0.314 1.069 1.534 0.314 1.069 1.534

Density, kg / 1 1.15 1.72 2.07 1.15 1.72 2.07

*) The emulsifier had the following composition:

Ingredient weight percent

Calcium oxide 56

Oleylamide 4

oleic acid 10

Dimerized oleic acid 10

Dispersant / Surfactant 8

Asphalt-like substances ... J.2

The Fann Viscometer and Stress Breakdown values for the compositions were also determined and are given in Table X below.

Table X

composition
12 3

6O0 ^ reading 100 140 300+ 71 146 282 58 112 300+ 3O0u reading 69 85 190 45 88 162 33 61 171 Plastic viscosity 31 55 - 26th 58 120 25th 51 - Yield Point 38 30th - 19th 30th 42 8th 10 - 200 reading 55 62 143 34 64 116 24 44 129 lOCl reading 38 36 84 21 38 66 13th 24 75 6 reading 8th 6th 11th 3 4th 9 2 3 10 3 reading 5 4th 8th 2 3 6th 1.5 2 5 Collapse under 200 124 160 200 160 124 124 80 82 voltage

Claims (17)

Patent claims: 1. Spacer fluid for keeping two well fluids separate from a water-in-oil emulsion with about 40 to 60 volume percent of a hydrocarbon oil and about 60 to 40 volume percent Water, an emulsifier with a fatty acid component and a surfactant Dispersant, characterized in that that the water content of the water-in-oil emulsion is fresh water that has a content of dissolved chloride salts of less than 1000 ppm and a total hardness of less than 500 ppm comprises that the emulsifier is about 1 to 20 percent by weight of a fatty acid amide with about 16 to 22 carbon atoms and about 55 to 78 percent by weight has a solid, particulate carrier material made of lime or diatomaceous earth, on its Surface the fatty acid amide is absorbed, and that the surfactant dispersant sulfonated paraffin, resin acid, a resin soap and / or a mixture of a sulfonated lignin with an oleylamide. 2. spacer fluid according to claim 1, characterized in that it is 0.043 to 0.144 kg of emulsifier contains per liter of spacing fluid. 3. spacer fluid according to claim 1 or 2, characterized in that it is 0.0014 to 0.0286 kg contains surfactant dispersant per liter of spacing fluid. 4. spacer fluid according to one of the preceding claims, characterized in that the Emulsifier contains up to 30 percent by weight of dimerized oleic acid and the spacer fluid through one Weighting material is set to a density of about 0.96 to 2.39 kg / 1. 5. spacer fluid according to any one of the preceding claims, characterized in that the Emulsifier contains about 3 to 15 percent by weight oleic acid. 6. spacing fluid according to any one of the preceding claims, characterized in that it is about 1 to 20 percent by weight, based on the total weight of the emulsifier, of a particulate Contains asphalt. 7. spacer fluid according to any one of the preceding claims, characterized in that it is about Contains 45 to 55 parts by volume of oil and about 45 to 55 parts by volume of fresh water. 8. spacer fluid according to one of the preceding claims, characterized in that the fatty acid amide of the emulsifier is an oleylamide, which is produced by condensation of oleic acid with diethanylamine is formed. SS 9. spacer fluid according to one of the preceding claims, characterized in that the surfactant dispersants are essentially equal parts by weight of waste sulphite liquor and an oleylamide formed from the reaction of oleyl chloride with n-methyltaurine, contains. 10. spacer fluid according to claim 5, characterized in that the emulsifier is about 5 to Contains 15 percent by weight oleic acid. 11. spacer fluid according to one of the preceding claims, characterized in that the Hydrocarbon oil is diesel oil. 12. spacing fluid according to claim 5, characterized characterized in that the oleic acid is undistilled, impure oleic acid formed from oleic. 13. spacer fluid according to claim 8, characterized in that the emulsifier is about 65 to 70 percent by weight calcium hydroxide as a lime component and about 3 to 10 percent by weight of the oleyl amide. 14. spacer fluid according to claim i3, characterized in that it is about 45 to 55 parts by volume Contains oil and about 45 to 55 parts by volume of fresh water. 15. spacer fluid according to claim 14, characterized in that the emulsifier is about 68.1 percent by weight Calcium hydroxide, about 4.9 percent by weight oleylamide and about 10 percent by weight Contains dimerized oleic acid. 16. Spacer fluid according to claim 14, characterized in that the oil is diesel oil, which is in the Spacing fluid is present in substantially the same volume as the fresh water. 17. Use of the spacing fluids according to one of the preceding claims between a Cementing composition and a drilling mud.