Preparation method of core-shell radioactively labeled silicon carbide fracturing proppant

Abstract

The invention discloses a preparation method of a core-shell radio-labeled silicon carbide fracturing propping agent. The propping agent consists of a silicon carbide ceramic shell and a core material embedded with the radioactive substance, namely silicon carbide ceramic. The preparation method comprises the following steps: mixing silicon carbide, aluminum oxide, kaolin, bentonite, talcum powder and dolomite according to a certain proportion to obtain mixed powder; mixing one part of the powder with barium-131-containing barium salt having radioactive activity, and pelleting to obtain the core material; spraying the same binding agent to the other part of the powder, and covering the core material as an initiator to form the silicon carbide shell free of radioactive substance; sieving, drying and sintering to obtain the core-shell radio-labeled silicon carbide fracturing propping agent. By virtue of excellent pressure-resistance, temperature-resistance and acid-resistance performances of silicon carbide as well as the core-shell structural design, the dissolving loss ratio of radioactive isotope in the finished product is reduced to the greatest extent, and under 102MPa, breakage rate is less than 5% and acid solubility is less than 1%.

Description

technical field [0001] The invention relates to a method for preparing a radiolabeled proppant used in the fracturing process of oil and natural gas wells, in particular to a core-shell type silicon carbide proppant with the radioactive isotope barium-131 ​​as the labeled isotope, which is used for determining formation fracture morphology, inspection The invention relates to the distribution state of proppants in oil and gas wells, belonging to the field of oil production (gas) additives. Background technique [0002] Hydraulic fracturing technology is widely used in the process of oil and natural gas development, that is, injecting high-pressure liquid into the formation through oil and gas wells, creating artificial fractures in the reservoir to improve its permeability, and then increase oil and gas production. Generally, the production of a single well can be increased by 2-3 times, or even more, and it is a widely used means of increasing production in the exploitation...

AI Technical Summary

Problems solved by technology

However, this problem has not been well resolved until now.

Most of the radiolabeled ceramsite proppants used for fracturing tracer analysis in the prior art have the risk of dissolution and loss of radioactive substances inside the ceramsite during injection into the formation

State-of-the-art radiolabeled resin tracer particles, the strength of the resin is low, and it is difficult to resist the high pressure and temperature during the fracturing process

Although the radiolabeled coated ceramsite proppant in the prior art reduces the risk of radioactive material dissolution to a certain extent, the risk of radioactive material in the proppant to dissolve and pollute the environment has not been fundamentally resolved, because the ceramsite proppant Although the compressive strength of natural quartz sand and phenolic resin-coated sand has been improved, when the closing pressure increases, its breakage rate can still reach 10-30%, and there is also the risk of radioactive substances leaching