Fire-resistant non-injury fracturing fluid thickening agent and preparation method and usage thereof

Abstract

The present invention is thickener for heat resistant no-harm fracturing fluid and its preparation process and use. The thickener in the general expression of R1-X-(EO)m(PO)n-Y, where, R1 is long chain hydrophobic group, EO is ethoxy group, PO is 2-oxidized propyl group, m and n are average addition molar numbers, X is linking group ether bond, ester bond or amido bond, Y is hydrophilic group quaternary ammonium group, carboxyl group, sulfuric group or sulfonic group, is prepared through esterification or addition and further reaction. When the thickener is applied, the thickener in 1-3 weight portions and high temperature stabilizer in 0.05-0.4 weight portion are added into base fluid compounded with halogen salt in 2-3 weight portions and water in 100 weight portions to obtain heat resistant no-harm fracturing fluid for increasing yield of oil-gas field.

Description

Technical field: [0001] The invention belongs to the technical field of fracturing fluids in oil and gas fields, and in particular relates to a small-molecule surfactant thickener for high-temperature-resistant and harmless fracturing fluids and a preparation method thereof. Background technique: [0002] U.S. "International Society of Petroleum Engineers Journal" 1998 page 43 (article number SPE39785) once reported that the plant glue fracturing fluid widely used in the oil and gas field fracturing stimulation is not enough to pump into the formation after the completion of the construction. 40%, a large number of "non-proppant solids" remaining inside the formation will block artificial diversion fractures and formations, making formation permeability unable to be significantly improved and seriously reducing oil recovery. [0003] U.S. Patent U.S.P.5,551,516 proposes a clean fracturing fluid based on small-molecule surfactants, which adjusts its viscosity by adjusting the...

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Problems solved by technology

However, because the main active ingredient used in it is dihydroxyethyl ammonium chloride, which needs to be prepared by selective catalytic hydrogenation under high temperature and high pressure conditions. Not only is the process more complicated and dangerous, but it is also expensive, and the cost is lower than that of ordinary plant glue. More than 20 times that of lysate, it is difficult to obtain large-scale promotion and application

[0004] Chinese patents CN1439691 and CN1621484 propose small molecule surfactant fracturing fluid ratio with long carbon chain alkyl trimethyl quaternary ammonium salt and oleic acid as main components The cost of foreign clean fracturing fluids has been greatly reduced, about three times the cost of vegetable gum fracturing fluids. Unable to form stable worm-like aggregates, it is only suitable for hydraulic fracturing operations in low-temperature formations with temperatures below 80°C

[0005] China.com "Suggestions on my country's Oil and Gas Resources Development Strategy" (Chen Zhouqi, www.china.org.cn, 5 / 3 / 2002 ) pointed out that many major oil fields on land in my country have entered the middle and late stages of development, and low-permeability or ultra-low-permeability oil and gas reservoirs with a depth of more than 3,500 meters account for more than half of the total recoverable reserves. The inevitable trend faced by the oil field, the existing fracturing fluid can no longer meet the needs of my country's energy exploitation, and it is an urgent task to develop a non-harmful fracturing fluid with good temperature resistance and moderate cost

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