Temporary plugging workover fluid and preparation method thereof

Abstract

The invention discloses a temporary plugging workover fluid and a preparation method thereof, belonging to the field of oil field chemistry. Based on 100 parts by weight, the temporary plugging workover fluid includes: 0.96-2.7 parts of flour balls, 0.48-1.35 parts of resin balls, 1.92-4.5 parts of swelling inhibitors, 0.29-0.45 parts of suspending agents, and 0.19-0.19 parts of fiber synergists 0.27 parts, 0.10-0.41 parts of antiscalant, 0.19-0.32 parts of degradation agent, and the balance is water; flour balls are mixed with wheat flour and floating beads with a mass ratio of 6:4-7:3, added water to mix, squeezed Made by pressing, cutting, forming and drying; the density of flour balls is 0.97‑1.02g / cm 3 , the particle size is 2‑4mm; resin balls are mixed with petroleum resin and floating beads with a mass ratio of 7:3‑8:3, then mixed with isopropanol and silane coupling agent, extruded, cut, shaped, and dried Prepared; the density of resin balls is 0.97‑1.02g / cm 3 , the particle size is 3-5mm; the fiber synergist is polyvinyl alcohol fiber; the diameter of polyvinyl alcohol fiber is 0.01-0.03mm, and the length is 3-5mm. The temporary plugging and workover fluid can form a temporary plugging layer with compact structure, excellent mechanical strength and pressure bearing capacity, and will not cause damage to the reservoir.

Description

technical field [0001] The invention relates to the field of oilfield chemistry, in particular to a temporary plugging workover fluid and a preparation method thereof. Background technique [0002] The leakage of workover fluid to the formation (referred to as lost circulation) not only affects the normal production of oil wells, but also pollutes the reservoir, causing loss of oil and gas production and economic losses to the oil field. The reasons for lost circulation include: high reservoir permeability, loose rock cementation, large pressure difference between reservoir and working fluid, etc. In the workover operation, the use of temporary plugging workover fluid can form a temporary plugging layer in the reservoir to prevent lost circulation. [0003] Currently used temporary plugging and workover fluids include superabsorbent resin and water, which can form stagnant gel clumps in the reservoir, accumulate in the reservoir, and block pore throats, thereby slowing lost...

AI Technical Summary

Problems solved by technology

[0004] The water-absorbing resin has a large water-absorbing expansion multiple, and its strength decreases after water-absorbing expansion. The pressure-bearing capacity of the temporary plugging layer is small, the adaptable range is small, and the success rate of temporary plugging is low.

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