RU2288934C1 - Non-hardenable sealing grease - Google Patents

Abstract

FIELD: oil and gas production.

SUBSTANCE: invention relates to lubricating substances suitable for sealing threaded connection for oil-assortment subjected to repetitive screwing, which substances include consistent organic base, in particular polyisobutylene and/or butyl rubber, and inert filler, namely furnace carbon black.

EFFECT: enhanced sealing power and resistance to thermocyclic loadings.

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Description

The invention relates to the oil and gas industry, and in particular to substances used to seal threaded joints of oil assortment pipes subjected to single or multiple screwing.

Closest to the technical nature and purpose of the present invention is an uncured sealant lubricant of threaded joints of oil pipes of the assortment, including a consistent organic base - fat composition, and an inert filler [1]. The specified lubricant is characterized by low sealing ability due to poor adhesion to the thread surface and low resistance to thermal cyclic loads.

When creating the invention, the problem was solved of increasing the sealing ability and resistance to thermocyclic loads.

The solution to this problem is achieved by the fact that the uncured sealing grease of the threaded joints of oil pipes of the assortment, including a consistent organic base and an inert filler, contains polyisobutylene and / or butyl rubber as a consistent organic base, and furnace carbon black as an inert filler in the following ratio of components, wt.%:

Polyisobutylene and / or Butyl Rubber 50-70 Carbon black rest

2 compositions of the known non-solidifying lubricant were prepared (fat composition and furnace carbon black of grades P-245 and P-324 according to GOST 7885-86) with an average content of components and 12 compositions of the uncured sealing grease according to the invention:

- polyisobutylene grades PIB-800 and PIB-100 according to TU 38.401-58-333-2004 and furnace carbon black grades P-245 and P-324 in accordance with GOST 7885-86;

- butyl rubber of grades BK-1675N and BK-1675S according to TU 2294-021-48158319-2001 and furnace carbon black of grades P-245 and P-324 in accordance with GOST 7885-86 with an average and boundary content of components.

The preparation of the lubricant is carried out in the usual way in a paddle type mixer by mixing the components in a predetermined ratio. For this, for example, 6 kg of a viscous transparent liquid of polyisobutylene and 4 kg of granulated furnace carbon black are loaded into the mixer and mixed for 20-30 minutes until a homogeneous mass is obtained.

Resistance to thermocyclic loads was determined by the number of matured “cooling-heating” cycles from 25 to 95 ° C at the maximum stage with an in-tube gas pressure of 30 MPa in accordance with methodological recommendations [2]. The increase in sealing ability was estimated by the maximum sustained in-tube gas pressure in static conditions.

The data given in the table indicate that the proposed non-curable sealing grease with an optimal ratio of components has better properties than the known one, namely: the number of withstand thermal cycles increased by 1.9 times, and the sealing ability increased by 1.6 times.

Information sources

1. Lubrication thread sealing RUS / Technical conditions. TU 14-162-32-97 (prototype).

2. Determination of the density limits of threaded joints of casing and tubing with various sealing means / Methodological recommendations. - M.: VNIIGAZ, 1975.

Claims (1)

Non-curable sealing lubricant of threaded joints of oil pipes of oil assortment, including a consistent organic base and an inert filler, characterized in that it contains polyisobutylene and / or butyl rubber as a consistent organic base, and furnace black carbon as an inert filler in the following ratio of components, wt.% : Polyisobutylene and / or Butyl Rubber 50-70 Carbon black Rest