Consolidating and sealing rock esp. core sample - by cement coating and thermal spray coating, esp. for oil recovery testing

摘要

In the consolidation and sealing of a cylindrical rock sample (1) by thermal spraying, onto the sample side surface, of a layer (3) of a ceramic selected from aluminium and zirconium oxides and titanium hydrides, then a layer (4) of refractory metal alloy selected from nickel-chronium alloys and nickel and titanium alunimides, and finally a layer (5) of nickel alloy, the novelty is that, prior to the ceramic layer applications, the side surface is made uniform by a (pref. ceramic) cement which resists the hot spray temp. of the carmic layer. Pref. the treated sample is sheathed with a fluid-tight heat shrinkable material selected from polyolefins and copolymers of vinylidene fluoride and hexafluoropropylene. The cement is suitably a ceramic cement of the type 'Cerastil' (RTM). The ceramic layer (3) is pref. a 1mm. thick ZrO2 layer. The refractory metal alloy layer (4) is pref. a 1mm thick Ni-Al alloy (e.g. 95% Ni-5% Al) layer. The Ni alloy layer (5) is e.g. a 0.7,, thick Ni-Cr-B alloy alloy layer. The heat shrinkable material is pref. a 2.5mm thick sheath (6) of an irradiated polyolefin which is internally coated with a glue (e.g. an epoxy glue such as polyamine resin) and which is shrunk at about 150 deg. C.. USE/ADVANTAGE - The process is useful for sealing core samples prior to laboratory oil recovery tests involving compressed air injection. The initial cement layer eliminates local asperities and seals sample surface voids.