Chemical fracturing fluid for hot dry rock

Abstract

The invention relates to chemical fracturing fluid for hot dry rock, which is prepared by mixing fluoboric acid, polyamino polyether methylene phosphonate and aluminum chloride hexahydrate. After the prepared chemical fracturing fluid is injected into a thermal reservoir of the hot dry rock, fluoboric acid is hydrolyzed to generate HF (hydrogen fluoride) gradually, the reaction speed with a stratum is lower, and deep penetration can be achieved. Polyamino polyether methylene phosphonate as polyatomic acid, can be decomposed into hydrogen ions at multiple stages, acts on the stratum for a long time, extends a penetration distance of chemical fracturing, further achieves a deep thermal reservoir transformation effect and has performance such as low speed, low damages, scale prevention and corrosion inhibition; simultaneously, phosphonate of polyamino polyether methylene phosphonate has significant absorption and water-dampness characteristics which can catalyze reaction between hydrofluoric acid and quartz and allow the corrosion speed of the quartz to be increased with time; and the improvement on the radial deep penetrability of the reservoir is facilitated.

Description

Technical field: [0001] The invention relates to a hot dry rock development enhanced thermal reservoir transformation technology of a geothermal system, in particular to a chemical fracturing fluid used in a geothermal well deblocking treatment process. Background technique: [0002] Geothermal resources, due to their clean, renewable and extensive spatial distribution, have become a renewable and clean energy that is mainly researched and developed by countries all over the world. They are mainly divided into hydrothermal type and dry hot rock type. The world's current mining and utilization of geothermal resources are mainly hydrothermal geothermal. Hot dry rock is a hot rock mass without water or steam, mainly various metamorphic rocks or crystalline rocks. Hot dry rock is generally buried at a depth of 3-10km from the surface, and its temperature range is very wide, between 150-650°C. At present, hot dry rock geothermal resources refer to hot rock masses with shallow b...

AI Technical Summary

Problems solved by technology

However, in the high-temperature environment of thermal reservoirs, the reaction speed of soil acid and rock mass minerals is very fast, and it disappears near the injection site, making it impossible to penetrate deep into the thermal reservoir; secondly, the reaction between HF and rock mass minerals will produce Precipitates such as silicic acid, metasilicate, and fluoride can block fracture channels, thereby significantly affecting the permeability of thermal reservoirs; thirdly, earth acid has strong corrosion, which is more serious for wells and casing strings.

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