Fracturing fluid pad fluid for optimizing size of in-situ self-generated proppant and application thereof
A fracturing fluid pad fluid is applicable to a calcium-rich reservoir and composed of clear water, phosphate, pH regulator and Ca 2+ chelator, wherein, for 100 weight parts of clear water, the content of the phosphate is 1 to 10 weight parts, the volume molar concentration of the pH regulator is 1 to 5 mol/L, and the volume molar concentration of the Ca 2+ chelator is 0.001 to 1 mol/L; the pH regulator is urea, ammonia water, propanamide and the like, and the Ca 2+ chelator is EDTA and glutamic acid and the like. The present disclosure increases the average particle size of the proppant particles generated by hydrothermal reaction of formation minerals, thereby improving its propping effect in the formation micro-fractures.
1 . A fracturing fluid pad fluid for optimizing a size of an in-situ self-generated proppant, applicable to a calcium-containing reservoir, wherein, the mass fraction of calcium in formation minerals in the calcium-containing reservoir is greater than 50%, and the fracturing fluid pad fluid consisting of:
water, phosphate, pH regulator and Ca 2+ chelator,
wherein, for 100 weight parts of water, the content of the phosphate is 7 weight parts, the volume molar concentration of the pH regulator is 1 mol/L, and the volume molar concentration of the Ca 2+ chelator is 0.5 to 1 mol/L;
the phosphate is at least one of diammonium hydrogen phosphate, ammonium dihydrogen phosphate, dipotassium hydrogen phosphate, potassium dihydrogen phosphate, disodium hydrogen phosphate, sodium dihydrogen phosphate and sodium phosphate,
the pH regulator is urea, and
the Ca 2+ chelator is glutamic acid.