RU2002134190A - METHOD FOR ELIMINATING COMPLICATIONS IN A WELL - Google Patents

Claims (8)

1. A method for eliminating complications in a well, comprising injecting a cement slurry in the form of a dispersion of a water-swellable polymer, in which a water-swellable polymer is used as a dispersed phase, holding it in the well and pumping, characterized in that it is pumped into the well before the water dispersion of the water-swellable polymer a buffer of fresh water, moreover, the volume of the buffer must be not less than the volume of the aqueous dispersion of the water-swellable polymer, and the concentration of the water-swellable polymer in the dispersion medium is determined in accordance with with injectivity of the isolated section of the well, characterized by a relationship between the buffer injection rate of 20 m ³ / h and excess pressure on the isolated section according to the table:

2. The method according to claim 1, characterized in that at an overpressure in the range of 0.5-12 MPa, after injection of an aqueous dispersion of a water-swelling polymer, cement is injected. 3. The method according to claim 1, characterized in that in the presence in the insulated interval of fissured-cavernous and porous media after injection of the buffer and the aqueous dispersion of the water-swelling polymer, a cement slurry is injected into the well, hardening in time, for example, cement mortar, and at a constant pressure fillers are introduced into the wellhead, and when the injectivity of the insulated section is 20 m ³ / h at a pressure of 1-12 MPa, the cement is injected after the water-swellable polymer reaches dispersion in a medium of maximum potential for swelling. 4. The method according to claim 3, characterized in that for all types of insulation work with a break between the injection of the aqueous dispersion of the water-swellable polymer and the cement composition hardening in time, they are first pumped through tubing until it leaves them with an open annulus, then the annular space is closed, and this moment is determined by the equality of the pressure of the liquid column in the annular space and the pressure of the liquid column in the tubing. 5. The method according to claim 1, characterized in that when isolating finely porous or finely fractured media, filtering through which overcomes the initial pressure gradient, followed by a buffer injected under pressure above the initial pressure gradient, a dispersion of a water-swelling polymer with individual particles in a gel is pumped condition, and at the end of the injection, filler is introduced in the form of a rubber powder. 6. The method, characterized in that during selective isolation of the flooded formation, a dispersion is pumped into it from a water-swellable polymer closed on an inert liquid thereto, with injection to it and after buffers also from liquids inert to the water-swellable polymer, for example synthetic fatty acid esters, a filler, rubber crumb, is introduced into the second buffer, and a buffer of fresh water is pumped in front of the first buffer, sufficient for swelling of GNP in full. 7. The method according to claim 6, characterized in that in the presence of natural bottom water in the flooded formation after injection of the dispersion of the water-swellable polymer, closed on a liquid inert to the water-swellable polymer, and buffers, thereafter, the water dispersion of the water-swellable polymer and grouting composition hardening over time are pumped. 8. The method according to claim 1, characterized in that if there are several layer-by-layer aquifers and oil strata in the productive stratum, multiple sequential injection of water-swellable polymers is carried out with appropriate buffers that are closed on water and an inert liquid.