SU1206431A1 - Method of isolating bottom water in oil well - Google Patents

Description

The invention relates to the oil and gas production industry, in particular to methods for isolating formation water in oil wells.

The purpose of the invention is to determine the reliability of isolating the water in an oil well by increasing the flow rate of trains.

The method is implemented as follows.

After opening the oil-bearing horizon with infused water into the well, drill pipes are lowered into the well by a sandblasting puncher and installed at 0.5–1 m Bbuiie of the oil-oil contact. Then, rotating the drill string, water jetting is carried out at an acceptable maximum pump capacity. As a result, a horizontal disc-shaped cavity is formed in the formation.

Then, the well is washed and the cavern zone and the wellbore are treated to a bottom-hole successively with an 8-10% aqueous solution of calcium chloride and a silicate-fixing solution of the following composition,

CPU with /

May / available liquid

glass (sodium silicate) 4.4-7.1

Carboxy methyl cellulose 0.2-0.4 Technical water95.4-92.5

The TFR volume is determined based on the diameter of the well and the power of the interval being processed.

Next, a hydromechanical packer (GMF) is grinded into the well, installed at 1-2 m above the cavity, and hydraulic fracturing is performed by injecting process water and increasing the pressure in the subpacker. At the same time due to clogging of pores and cracks

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the reservoir in the hydraulic fracture zone provides a rapid increase in the well pressure, stress concentration at the periphery (top) of the artificial cavity and the formation of a horizontal directional fracture.

After fracturing the formation and determining its irregularity, a pumping solution is injected into the reservoir, treated with a PVA-TP polyvinyl slug, which is forced through with full displacement from the wellbore to the nlast.

The well was drilled to a depth of 1120.8 m, it opened a 5.2 m thick oil-bearing formation with subbasic water.

At a depth of 1138 m, an OP-4 hydro-sand jet drill is lowered into the well. Hydro sandblasting is performed at a depth of 1125 m with a pressure at the mouth of 14–15 MPa and pump performance M Vc. Pod in perforator and lowering

0 open end of drill pipe (OKBT), nromyut well with water. Next, they inject 3 m of a 10% aqueous solution of calcium chloride, 0.5 m of water, 3 m of the RMS and push them into the annular space, and then onto the day surface. After lifting the OKBT, the packer is lowered to a depth of 1124 m. The formation is fractured. Then, 10 m of technical water and a cement slurry prepared from 8 tons of portland cement in a 1% aqueous solution of PVA-TR are pumped into the formation. The cement slurry is forced into the reservoir. Wellhead pressure is 8 MPa. The well is being worked out and drilled to the design depth. The well, perforated in the range of 1120.8-11123.6 m, continues to produce anhydrous oil, while the neighboring wells, drilled using conventional technology, were flooded.

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Claims (1)

METHOD FOR ISOLATING SUBSOIL WATER IN AN OIL WELL, including the creation of a disk-shaped cavity in the oil-water contact zone oriented in the horizontal plane, injection of the working agent under pressure sufficient for hydraulic fracturing, and subsequent filling of the disk-shaped cavity and the resulting cracks with grouting cement in order to improve the insulation reliability by increasing the length of cracks, the surface of the disk-shaped cavity is treated before injection of the working agent They are fixed with a fixing solution.