EP2247689A1

EP2247689A1 - Additive for cementing boreholes

Info

Publication number: EP2247689A1
Application number: EP09711767A
Authority: EP
Inventors: Roland Reichenbach-Klinke; Tinton Setiawan; Johann Plank
Original assignee: BASF SE
Current assignee: BASF SE
Priority date: 2008-02-23
Filing date: 2009-01-19
Publication date: 2010-11-10
Also published as: BRPI0907850A2; CA2715588A1; US20100317764A1; DE102008010795A1; US8470907B2; WO2009103579A1; CN101952387A; MX2010009247A; CA2715588C; RU2490294C2; RU2010138837A

Abstract

The invention relates to an additive based on a polyalkylene imine and a sulfonated formaldehyde-containing condensation product, and the use thereof as a fluid loss additive for the cementing of boreholes in the fields of crude oil and natural gas. Typical representatives of polyalkylene imines are polyethylene imine, polypropylene imine, and polybutylene imine, which can also be derivatised. Preferred condensation products are acetone/formaldehyde resins. Such additives which are left to ripen before being used, especially by being allowed to stand, have an especially low fluid loss value.

Description

Additive for cementing boreholes

The present invention is an additive based on a polyalkyleneimine and a sulfonated formaldehyde-containing condensation product and its use.

The use of polyalkyleneimines and in particular polyethyleneimine in building chemical compositions and especially as so-called fluid loss additive is well known. In this context, it is essential for achieving a sufficiently low fluid loss to use the respective polyalkyleneimine together with another component, since in particular the polyethyleneimine alone can not exert such an effect.

A fluid loss additive is understood to be a chemical composition used to control the leakage of liquid and, in particular, aqueous fluids from subterranean formations in connection with the drilling of oil and gas deposits. This loss of fluid poses a serious problem, particularly in cementing wells, as the aqueous phase of drilling fluids can adversely affect the nature and behavior of the slurry as well as the setting behavior of the cementitious composition employed. In addition, the uncontrolled discharge of liquid into or out of the subterranean formation usually causes significant damage to the rock formations, with the result that their permeability changes dramatically negatively.

For example, U.S. Patent 3,491,049 describes the use of polyethyleneimine together with an anionic surfactant as a fluid loss additive. Sulfonated naphthalene is a typical representative of the surface-active substance used in this case.

Also, a fluid loss additive is a reaction product between a polyethyleneimine and a high molecular weight sulfonated polymer, which is preferably a sulfonated polystyrene according to US 4,469,518.

Fluid loss additives based on polyethyleneimine can also be found in US Pat. Nos. 4,742,094 and 4,791,989. According to US Pat. No. 4,742,094, polyethyleneimine is used together with a sulfonated organic compound which is a lignosulphonate or a sulphonated naphthalene-formaldehyde condensate. The same composition is used in the method of cementing a well according to 4.791, 989. The use of a combination of polyethyleneimine, a sulfonated naphthalene / formaldehyde condensation product and an alkylbenzenesulfonate fluid loss additive is taught in US 5,340,860.

Thus, exclusively fluid-loss additives are known from the prior art which contain a combination of polyethyleneimine with a sulfonated naphthalene, a sulfonated polystyrene, a sulfonated naphthalene / formaldehyde resin or a lignosulfonate.

As previously described, the uncontrolled discharge of fluids into subterranean rock formations in the exploitation of oil and gas deposits poses a significant problem which, although reasonably well controlled by the existing fluid loss additives, still poses unpredictable risks can. It is therefore an object of the present invention to provide additional fluid-loss additives based on a polyalkyleneimine and a sulfonated formaldehyde-containing condensation product. These new additives should ideally have a significantly improved effect with a simultaneously optimized economy compared to the known additives. In addition, their accessibility through the use of commonly available starting materials should be possible without problems.

This problem was solved with a corresponding additive which contains as condensation product a sulfonated ketone / formaldehyde resin.

Surprisingly, it has been shown with this new additive that not only the task could be completely fulfilled, but that it compared to the previously used compositions causes a further significantly reduced fluid loss, the fluid-loss effect even over the life of the Additivs or on its maturation can be controlled.

Overall, it has turned out to be advantageous if at least one compound of the series polyethyleneimine, polypropyleneoxyimine and polybutyleneimine is contained in the additive as a typical representative of the alkyleneimine component. In particular, polyethyleneimines have been found to be particularly suitable, which may also be substituted. These include N-methyl, N-acetyl and N-butyl polyethyleneimine.

In the present invention, polyethyleneimines having the general formula (C ₂ H ₅ N) _n and having a preferred molecular weight M w of from 10,000 to 3,500,000 g / mol are particularly suitable. Molecular weights M w of from 1 000 000 to 3 000 000 g / mol and in particular from 1 500 000 to 2 500 000 g / mol are to be regarded as particularly advantageous. Additives in which the condensation product contains as ketone component at least one member of the mono- and diketones and preferably acetone, butanone, pentanone, hexanone and cyclic ketones such as cyclohexanone are considered to be preferred in the context of the present invention. Acetone / formaldehyde resins are particularly well suited.

In general, the additive according to the invention is not subject to any restriction with regard to the distribution of the components contained therein. However, it is particularly advantageous if the polyethyleneimine and the condensation product are present in a mass ratio of 20 to 1: 1, preferably 15 to 5: 1 and in particular 11 to 9: 1.

Also with regard to the condensation product contained in the additive, the claimed additive can be varied in wide ranges, which applies in particular to the above-mentioned ketonic representatives. In certain applications, it has proved to be particularly advantageous if the condensation product is a mixture of at least one ketone / formaldehyde resin and a sulfonated naphthalene or melamine / formaldehyde condensation product and / or a polycarboxylate contained. The proportion of ketone / formaldehyde resin should be in a range of 40 to 90 wt .-%, with ranges of 50 to 80% and in particular 60 to 70 wt .-% are particularly suitable. The polycarboxylate ether component is preferably a co-polymer consisting of two monomer units, wherein the moiety a) is an olefinically unsaturated monocarboxylic acid comonomer or an ester or a salt thereof, or an olefinically unsaturated sulfuric acid co-monomer. Monomer or a salt thereof, and the unit b) a co-monomer of the general formula (I)

(-CH ₂ -CR ₂ -)

where Ri for

- (C _m H _2m O) χ (CnH _2n O) _y - (CH ₂ -CH-O) ZR ₄

R ₃

and R _{2 is} H or an aliphatic hydrocarbon radical having 1 to 5 C

atoms; R ₃ = unsubstituted or substituted aryl radical and preferably phenyl, and R ₄ = H or an aliphatic hydrocarbon radical having 1 to 20 C atoms, a cycloalkenyl radical Liphatic hydrocarbon radical having 5 to 8 carbon atoms, a substituted aryl radical having 6 to 14 carbon atoms or a member of the series

: - R _5, - O- C- R ₆ is -C-OH, - O- C- (NH) R ₇ wherein R5 and R7 are each an alkyl, aryl, aralkyl, or alkaryl radical and Rβ for an alkylidene, arylidene, aralkylidene or alkarylidene radical, and P = O to 3, m, n = 2 to 4; x and y independently represent 50 to 350 and z = 0 to 200.

Preferably, the additive according to the present invention should be present as a dry mixture or as an aqueous solution. In addition, it may contain as further component a defoamer (such as tributyl phosphate, representatives based on mineral oil or silicone, silicone-free polymers), but also other common additives in the oil field field, such as rheology modifiers.

In addition to the additive itself, the present invention also claims its use in the field of development, exploitation and completion of underground oil and gas deposits. In particular, its use as a fluid-loss additive in the cementation of boreholes in the oil and gas sector and in deep drilling is in the foreground.

In the mentioned applications, the additive should preferably be added to the cementitious dry mix and / or the mixing water.

It has turned out to be particularly surprising that the additive develops its fluid-loss effect in a particularly significant manner when it is subjected to ripening prior to its addition to the cementitious dry mix and / or the mixing water. For this maturation, the present invention provides, in particular, for allowing to stand for an extended period of time. In particular, when the additive is over a period of at least 12 hours, preferably at least 48 hours, more preferably at least 10 days, and most preferably at least 30 days, it develops during its application a particularly pronounced low fluid loss in the respective subterranean formations. Overall, it can thus be stated that the claimed additive brings about a particularly good water retention capacity if the two main components, namely the polyalkyleneimine and the ketone / formaldehyde condensation product, are formulated before mixing into the cement slurry and then rest for some time. For this purpose, the additive according to the invention is ideally prepared in a first step in the form of a mixture of the two components polyethyleneimine and condensation product as aqueous solution, before this solution, after a longer service life, finally in the second step with the cementitious mixture, optionally the defoamer and other additives, as well as the remaining mixing water mixed. Depending on the length of the service life, an increasingly low fluid loss is found in practical use.

Finally, based on this finding, the present invention also takes into account a variant of use in which the ripening takes place in aqueous solution, and preferably in at least 10%, and more preferably in at least 20%, aqueous solution.

The following examples illustrate the described advantages of the present invention.

Examples

The preparation of cement slurries and the determination of their properties (fluid loss, rheology) were carried out according to API Recommended Practice for Testing Well Cements 10 B, 23rd Edition, April 2002 (API 10B).

Example 1 :

This example illustrates that the manner of mixing the cement slurry has a significant impact on the fluid loss reducing properties of the additive of the present invention.

For this purpose, the following cement slurry was investigated:

800 g Class G Cement (Dyckerhoff Black Label) 1% bwoc Polyethyleneimine Lupasol SK (BASF SE)

0.1% bwoc acetone-formaldehyde sulphite condensate Meieret K3F (BASF Construction Polymers GmbH)

352 g of deionized water

1 g defoamer (tributyl phosphate)

When the cement slurry was stirred, the powdered acetone-formaldehyde-sulfite condensate was first dry-mixed with the cement, as described in the general practice, and then mixed with the mixing water which already contained the liquid components polyethyleneimine (PEI) and tributyl phosphate. There was a significantly lower, but still relatively high, fluid loss of 332 ml compared to the prior art. Alternatively, in a first step, the inventive additive mixture of the two components polyethyleneimine (PEI) and acetone-formaldehyde-sulfite condensate (AFS) was prepared as an aqueous solution. In a second step, this solution was stirred with the cement, the defoamer and the remaining mixing water. Following this procedure, a significantly lower fluid loss of 70 ml was measured. In addition, as shown in the following table, a significant influence of the lifetime of this additive solution before its addition to the cement on the effect as a fluid-loss additive is observed:

Example 2:

This example makes it clear that the additive according to the invention (formulation 1) has improved properties compared to the combinations of polyethyleneimine with other sulfonated polymers or flow agents (comparative formulations 2, 3, 4):

Rheology and fluid loss after mixing the additives with the cement slurry according to the standard procedure:

Rheology and fluid loss after 5 min life of the respective PEI-fluid mixture before mixing the cement slurry:

Rheology and fluid loss after 900 min of service life of the respective PEI / flow agent mixture before mixing the cement slurry:

*) Since a strong sedimentation was observed at a dosage of 0.1% bwoc of the polycarboxylate ether, here the amount was reduced to 0.05% bwoc.

While with the use of naphthalene-formaldehyde sulfite condensate, melamine-formaldehyde-sulfite condensate or polycarboxylate ethers (comparative approaches 2, 3, 4) no significant influence of the service life of the PEI / flow agent mixture on the fluid loss can be observed, occurs in the inventive combination PEI / AFS (approach 1) a significant reduction in the fluid-loss value.

Claims

claims

1. An additive based on a polyalkyleneimine and a sulfonated, formaldehyde-containing condensation product, characterized in that it contains as a condensation product a sulfonated ketone / formaldehyde resin.

2. Additive according to claim 1, characterized in that the polyalkyleneimine is at least one member of the series polyethyleneimine, polyvinyl nimine, polybutyleneimine and in particular polyethyleneimine.

3. Additive according to one of claims 1 or 2, characterized in that it comprises as polyethyleneimine a compound of general formula (C2H ₅ N) _n having a preferred molecular weight Mw of 10,000 to 3,500,000 g / mol, in particular from 1,000,000 to 3,000,000 g / mol and more preferably from 1500000 to 2500000 g / mole.

4. Additive according to one of claims 1 to 3, characterized in that the condensation product as ketone at least one member of the mono- and di ketones, preferably acetone, butanone, pentanone, hexanone and cyclic keto such as cyclohexanone, and in particular acetone ,

5. Additive according to one of claims 1 to 4, characterized in that it contains the polyethyleneimine and the condensation product in a mass ratio of 20 to 1: 1, preferably 15 to 5: 1 and in particular 11 to 9: 1.

6. Additive according to one of claims 1 to 5, characterized in that it comprises as condensation product a mixture of at least one ketone / formaldehyde resin and a sulfonated naphthalene or melamine / formaldehyde

Contains condensation product and / or a polycarboxylate ether, with a preferred proportion of the ketone / formaldehyde resin from 40 to 90 wt .-%.

7. Additive according to one of claims 1 to 6, characterized in that it is present as a dry mixture or aqueous solution.

8. Additive according to one of claims 1 to 7, characterized in that it contains as further component a defoamer.

9. Use of the additive according to one of claims 1 to 8 in the field of development, exploitation and completion of underground oil and gas deposits.

10. Use of the additive according to claim 9 as a fluid loss additive in the cementation of boreholes in oil and gas and deep boreholes.

1 1. Use according to any one of claims 9 or 10, characterized in that the additive of the cementitious dry mix and / or the mixing water is added.

12. Use according to one of claims 9 to 1 1, characterized in that the additive before its addition to the cementitious dry mix and / or the mixing water a maturation, preferably by standing, is subjected, in particular over a period of at least 12 hours, preferably from at least 48 hours, more preferably at least 10 days, and most preferably at least 30 days.

13. Use according to claim 12, characterized in that the ripening is carried out in aqueous solution, preferably in an at least 10% and more preferably in an at least 20% solution.