SU960217A1 - Drilling mud - Google Patents

Description

(54) DRILLING SOLUTION

one

The invention relates to the oil industry, in particular to the chemical treatment of water-based clay muds.

Known drilling fluid treated with N-oxide- -nitropyridine to suppress bacterial and fungal microflora CU

Possessing a broad antimicrobial spectrum of action, this compound is not very promising, since only laboratory methods for its preparation are known to it, and at present there are no technological developments that allow its production to be organized. In addition, complex, multi-step synthesis of M-oxide-4-nitropyridine leads to the high cost of this compound.

The closest in technical essence to the invention is a drilling fluid containing clay, water, carboxymethylcellulose and the inhibitor of its microbiological destruction G2}.

In tab. Table 1 presents examples of the preparation of drilling fluids with average and limiting values of the ingredients included in the proposed composition,

In tab. 2 presents data from which it is clear that the bactericidal additive 1,2-di (benzilamino) prbpana is known provides for the suppression of the viability of microorganisms and the improvement of the technological parameters of drilling mud for a limited period of time (2 weeks). When curing the drilling fluid for 8 weeks. due to a decrease in the bactericidal activity of 1,2-di (benzylamino) propane, the number of microorganisms increases to 187 thousand cells in 1 ml of solution; after treatment with the proposed inhibitor (dialkylamine), microbial cells are not detected in the solution. The increase in the number and biomass of microorganisms in a solution containing 1,2-di (benzylamino) propane is accompanied by a deterioration in the performance properties of the drilling fluid, in particular by increasing the water loss from t cm to 11 cm and the complete loss of structural and mechanical properties due to using organic polymers (CMC) by microbial cells as a food source. Being an effective inhibitor of microflora in drilling fluids, 1,2-di (benzylamino) propene is widely used in drilling shallow wells (2000–2500 m) for a short period of time (2-3 months). However, due to the intensification of oil production, which required a significant increase in the volume of drilling of deep non-exploratory wells in the current grid, it became necessary to use drilling fluids with stable parameters for a long period of time (1-3 years). The aim of the invention is to increase the degree of protection of carboxymethyl lulose from microbiological decomposition while maintaining the rheological properties of devices. The goal is achieved by the fact that drilling mud contains dialkylamines of about. Formula NHR, where (CH), (-C), with the following ratios of components, weight: Clay 6,0-20,0 Carboxymethylcellulose 0,75-1,5 Dialkylamines (dimethylamine 0,25-0,5 or Diethylamine) Water Else The introduction of the proposed dialkylases ensures the preservation and maintenance of the antiseptic properties and stable values of fluid loss and the structural and mechanical properties of the drilling fluid over the entire observation period (8 weeks), does not reduce the electrical resistivity of the solutions, which is a necessary condition for and accurate electrical rometricheskih research in the well. The addition of dialkylamines can reduce the swelling of clay, which will allow the use of such solutions when drilling at intervals of unstable, prone to collapses and destruction, sediments. The invention will make it possible to reduce the effective bactericidal concentration of the inhibitor by 2 times (from 0.5 to 0.25 wt.%) And at the same time prolong its action by at least 4 times, which gives an additional economic effect. In addition, dialkylamines (dimethyl-, diethylamines) are available commercial products produced by the chemical industry, which made it possible to carry out field tests of one of the proposed inhibitors. In particular, while drilling the deep well No. 70 of the Berkutovskaya area (design depth 4050 MJ of the Ishgulovskoye deep drilling expedition of the Bashneft association, July 1981, was tested as a bactericidal additive diethylamine (DEA). DEA additive in the amount of 0.25 weight. ensured the suppression of microorganisms in the drilling fluid from 2.6-10 to 15-10 in 1 ml of solution, i.e. more than 17 thousand times. Before the introduction of DEA, the drilling fluid was of poor quality, despite the significant consumption of chemicals (CIC, UShR, okzila, etc.) and was virtually uncontrollable, forcing Stop the well drilling process. After DEA treatment (after 2k hours), the parameters of the solution improved: the viscosity of the solution decreased from 31 seconds and the flow rate decreased from 28 to 20.5 cm, which allowed the well to resume drilling. provides a high degree of protection for polymers (such as CMC, starch), which are part of drilling fluids, from microbiological destruction, has good technological properties in terms of basic indicators (water loss, static shear stress, electrical resistance) .

Claims (2)

T. a b / 1 and c a 1 Formula of Invention 30 A drilling fluid containing clay, water, carboxymethyl cellulose and an inhibitor of its microbiological destruction, characterized in that, in order to increase the degree of protection of carboxymethyl cellulose from microbiological decomposition while maintaining the rheological properties of the solution , it as an inhibitor of microbiological destruction contains dialkylamines of the general formula NHR2, where (СНз), (), with the following ratios of components, weightD: eight 960217 Continued table. 2 at 40 No. 2 to 198 Clay6.0-20.0 Carboxymethylcellulose0, Dialkylamines (dimethylamine or diethylamine) 0.25-0.5 Water. The rest Sources of information, ntye into account during the examination 1. USSR author's certificate 58196, cl. From 09 K 7/02, 1968. 2. USSR author's certificate for application No. 2858i 95, cl. C 09 K 7/02, 0 (prototype).