Nitrogen foam fracturing fluid for fracturing of coal bed gas reservoirs and preparation method of nitrogen foam fracturing fluid

Abstract

The invention belongs to the field of oil and gas resources development, and particularly relates to a nitrogen foam fracturing fluid for fracturing coal bed gas reservoirs and a preparation method ofthe nitrogen foam fracturing fluid. Under the working conditions of shaft bottoms of coal bed gas wells, the nitrogen foam fracturing fluid for fracturing the coal bed gas reservoirs is prepared fromthe components in percentage by volume: 60%-90% of nitrogen and 40%-10% of a foaming agent aqueous solution, wherein the foaming agent aqueous solution is a mixed liquid and is prepared from the components in percentage by weight: 94.9%-90.9% of water, 1% of a foaming agent, 2% of a foam stabilizer, 0.1% of bactericide, 1%-2% of a discharge aiding agent and 1%-2% of an anti-swelling agent. The nitrogen foam fracturing fluid for fracturing the coal bed gas reservoirs is suitable for hydraulic fracturing of the coal bed gas reservoirs, oil reservoirs and gas reservoirs, no solid phase residuesexist, reservoir damage is small, filtration loss is less, seam forming is long, sand-carrying ability is high, used liquid is less, more than 50% is reduced, the gas is saw quickly, the production steps are simple, and the operability is high.

Description

technical field [0001] The invention belongs to the field of oil and gas resource development, and in particular relates to a nitrogen foam fracturing fluid for coalbed gas reservoir fracturing and a preparation method thereof. Background technique [0002] Coalbed methane, commonly known as "gas", is an associated resource in coal, and its main component is methane. Because coalbed methane exists in two states of free and adsorbed in coal deposits, among which coalbed methane exists mainly in the adsorbed state, which leads to serious problems such as low single well production and low recovery rate of coalbed methane wells. At the same time, the frequent occurrence of gas explosion accidents in the process of coal mining due to the ineffective extraction of coalbed methane has become the main factor threatening the safe and efficient utilization of coal resources in our country. The transformation of coalbed methane reservoirs by hydraulic fracturing is one of the main wa...

AI Technical Summary

Problems solved by technology

[0007] Aiming at the shortcomings of active water, jelly pressure and linear fracturing fluid used in hydraulic fracturing of coalbed methane reservoirs during the fracturing process, the reservoir damage is large, the fracture size is small, the stimulation effect is not obvious, and the drainage time is long. A preparation method of nitrogen foam fracturing fluid for coalbed methane reservoir fracturing was developed to overcome the above-mentioned shortcomings of active water, jelly and linear gel fracturing fluids, and to increase single well production and cumulative recovery after fracturing of coalbed methane reservoirs