Oil and gas well fracturing fluid for 180-200 DEG C high temperature strata

Abstract

The invention relates to an oil-gas well fracturing fluid used in a high-temperature stratum at 180 to 200 DEG C in an ultrahigh temperature compression fracture stimulation technique. The technical proposal comprises: the raw materials used by the fracturing fluid comprise the following components in percentage by weight: 0.3 to 0.6 percent of thickening agent, 0.1 to 0.7 percent of crosslinking agent, 0.3 to 0.6 percent of clay stabilizer, 0.2 to 0.6 percent of bactericidal agent, 0.1 to 0.4 percent of pH conditioning agent, 0.3 to 0.6 percent of temperature stabilizing agent, 0.2 to 0.7 percent of cleanup additive, 200 to 1500 ppm of gel breaker, 2 percent of potassium chloride, and 94 to 96 percent of water. The high-temperature fracturing fluid adopts high-temperature resistant hydroxypropyl carboxymethyl guargum as the thickening agent and uses a high-temperature crosslinking agent compounded from organic boron and organic zirconium. The fracturing fluid has the advantages of good shear resistance and temperature resistance, good gel breaking effect, friction resistance reduction and low permeability, wherein the viscosity can be kept between 70 and 80 MPa.s after the fracturing fluid is sheared for 120 minutes under the condition of 190 DEG C and 170s. The fracturing fluid is successfully applied to the Zhuanggu No.63 well of which the stratum temperature is 184.6 DEG C in Shengli Oil Field.

Description

technical field [0001] The invention relates to an oil and gas well fracturing fluid for 180-200 DEG C high-temperature strata used in ultra-high temperature oil and gas well fracturing stimulation technology transformation. Background technique [0002] The quality of oil and gas resources in my country is relatively poor. Among the remaining recoverable oil reserves, low-permeability or extra-low-permeability oil, heavy oil, heavy oil and burial depth greater than 3500m account for more than 50%; the recoverable resources to be proven will be those with greater burial depth, worse quality, marginal more difficult-to-use resources. Under the circumstance that recoverable and easy-to-recover reserves of oil are constantly decreasing, the exploration and development of oilfields has developed from marine, complex strata, deep wells, medium-deep wells and ultra-deep wells. These ultra-deep wells are generally above 4,000 meters. For oil and gas wells with a depth of more tha...

AI Technical Summary

Problems solved by technology

In order to increase production, the following problems are faced when fracturing deep and high-temperature oil and gas wells: the formation temperature is high, the fracturing fluid is required to have good temperature resistance, and because the fracturing fluid flows through a long pipeline, the experienced high The increase of shear time requires the fracturing fluid to have good viscosity recovery under high temperature and high shear, and also have delayed cross-linking properties to reduce flow friction

Today's existing fracturing fluids cannot meet these requirements, so it is an urgent task to develop an ultra-high temperature fracturing fluid with good temperature resistance and moderate cost (Chen Yuanqi, China Network "Suggestions on my country's Oil and Gas Resources Strategy" www .china.org.cn, 2002-3-5)

Existing fracturing fluids are generally used in formations below 120°C, and are less suitable for high-temperature formations (above 120°C), such as EP0302544A2, and fracturing fluids that can meet ultra-high temperature (above 150°C) formations are still very few in the market. It is rare, and the fracturing fluid that can meet the formation temperature above 180°C has not been reported in China

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