SU1093046A2 - Method of squeezing petroleum from seam - Google Patents

Abstract

METHOD OF OIL EXTRACTION FROM THE LAYOUT BY AUTH. St. No. 747191, about tl and by the fact that, in order to increase the oil recovery of the reservoir, the micelle solution is mixed with a water-soluble polymer before injection into the formation, and the amount of water-soluble polymer is 0.02-0.2% of the total mass of the mixture.

Description

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N5 The invention relates to the field of oil industry, in particular to methods for displacing oil from a pad. According to the main author. St. No 747191 by limes is a method of displacing oil from the reservoir, which consists in sequential injection of saline water and micellar solution with an upper phase into the formation, and a rim of saline water is injected with a salt concentration that exceeds the salt concentration of the aqueous phase of the micellar solution. The disadvantage of this method is low oil recovery of a reservoir that is not uniform in permeability. The purpose of the invention is enhanced oil recovery. The goal is achieved by the fact that during sequential injection into the formation. saline water and micellar solution with an external aqueous phase (the rim of saline water is pumped with a salt concentration exceeding the salt concentration of the aqueous phase of the micellar solution) the micelle solution is mixed with a water-soluble polymer with the water soluble polymer being 0 , 02-0.2% of the total mass of the mixture. Experiments show that an aqueous micellar solution (BMP) containing a polymer exhibits better oil-driving and rheological properties when it moves through the formation after it} 1ralized with water than a micelle solution that does not contain polymer. The improvement in oil production properties is due to a large decrease in interfacial tension at the border with BMP oil containing polymer than BIEP without a polymer, and the improvement in rheological properties due to the specific property of aqueous polymer solutions to exhibit the non-Newtonian flow pattern in the porous medium, as a result The coverage ratio of the injected chemical agent increases. Hydrolyzed poly arylamides, cellulose derivatives, biopolymers, polyethylene oxides, etc. are used as a water-soluble poly-gmer. Example 1 illustrates the oil-driving properties of BMP, containing and not containing Plyacrylamide, according to the proposed and known methods of oil displacement on a homogeneous reservoir model. BMP has the following composition, wt.%: Ammonium oil sulfonate of equivalent weight 5073.6 Hydrocarbon (oil included in oil sulfonate) 8.0 Ammonium sulfate 2.4 Water tap 86.0 The proposed method tests this BMP, containing 0.01% polyacrylamide molecular weight of 7-10 and a degree of hydrolysis of 15%, the petroleum extrusion capacity of these micelles of rnps solutions (MP) was determined by the following method. A reservoir model (core) 50 cm long and 1.1 cm in diameter, represented by quartz sand and having a porosity of 36% and a water permeability of 3.8 D, is full; reservoir water with a total salt content of 246 g / l is then forced out three pore volumes of Alakaevskaya core oil with a viscosity of 5.8 cP at 20 C. In turn, oil is forced out of the same formation water to the maximum water content of the outgoing fluid samples from the core. In this case, the final oil displacement reaches BOSI%. Then, 5% of the pore volume of the test micelle solution, containing or not containing polymer, are sequentially pumped into the core, 50% of the pore volume of the aqueous solution of polyac-Jrylamide, viscosity approximately equal to the viscosity of the liquid, then three pore volumes of water core. Experiments are carried out at room temperature. As a result, the oil-driving capacity of MP by the known method amounts to 72% of the oil remaining in the core after waterflooding, and MP with polyacrylamide by the proposed method is 87%. Example 2 illustrates the rheological properties of a micelle solution that contains and not soda: neighbors polyaquilamide using the proposed and known methods of oil displacement, I In this example, the rheological properties of Bi were evaluated on a non-uniform permeability model of the reservoir represented by parallel current tubes. injected fluids and with separate outlet tubes

displaced fluids, which allows to evaluate the effectiveness of chemical compositions separately for cores and in general for models

Two BMP with polyacrylamide were prepared by dissolving 0.1 and 0.2 g of polyacrylamide with a molecular weight of 7 x 10 and a degree of hydrolysis of 15% in 100 ml of BMP (0.1 and 0.2% polymer solution in BMP, respectively) ,

The reservoir model is heterogeneous in permeability; it is represented by two parallel cores 32 cm long and 2.5 cm in diameter, filled with quartz sand and marshallite. Permeability

jno water one core of 0.14 D, and the second 0.91-1.25 D.

. The reservoir model is treated with reservoir water with a total salt content of 246 g / l, then water is displaced with three pore volumes of oil core with a viscosity of 6 cP at 20 ° C, and oil is replaced with tap water to the maximum water content of the outgoing core samples. In this case, the residual oil content in the low-permeable core is 58-59%, and in the high-permeable 33-34%.

Four experiments were performed on the prepared inhomogeneous reservoir models, which allowed to evaluate the oil-driving and rheological capabilities of BMP, BMP with 0.1 and 0.2% polyacrylamide and separately polyacrylamide solution (without .BMP). The conditions are as follows:

1st and 2nd experiments — 0 is pumped into the formation model, 1 is the pore volume of the mineralized water model with a total salt content of 9 g / l, then 0.05 BMP pore volume with 0.1 or 0.2% polyacrylamide, 0, 5 pore volumes of a polyacrylamide solution with viscosity of 9.6 cP and 1-1.5 pore volumes of fresh water (according to the proposed method).

3rd experience - the same as 2nd experience, but instead of VIR with polyacrylamide is taken

BMP without polyacrylamide (by a known method) and

The 4th experiment is the same as the 2nd experiment, but without downloading a BMP, i.a. polymer flooding was simulated on a heterogeneous core.

Experiments are carried out at room temperature.

The oil-intake capacity of BHP (n) is determined by the total amount of oil displaced from the model, i.e., from both cores, and is expressed as a percentage of the amount of oil trapped in the model after the waterflood. The rheological capacity R of the studied chemical compositions was estimated by the ratio of the oil displacement coefficient from the low-permeable core to the oil displacement coefficient from the height of the permeable core. The greater this ratio, the better the rheological properties, i.e., the better the chemical composition regulates the mobility of liquids in the cores.

The results of the experiments are given in the table.

From these results it can be seen that the efficiency of both the oil-forcing and the rheological, the use of VHP by the proposed method is significantly higher than by the known method. In addition, the introduction of vrdor. Soluble polymer in BMP and using it according to the proposed method significantly improves the rheological ability of both BMP and aqueous solution of polyacrylamide, a synergistic effect of a mixture of BMP with PAA is observed (cf. experiment 1 with experiments 3 and 4 ).

The proposed method can be used both to increase oil recovery by injecting 0.05-0.2 of the pore volume of the rim, MP, and to intensify the operation of injection and oil-producing wells by processing the bottom-hole zone. 0.3-1.5 m MR per 1 m thickness of the layer nli perforation interval.

Claims (1)

METHOD FOR EXPLOSING OIL FROM THE STRING by ed. St. No. 747191, characterized in that, in order to increase oil recovery, the micellar solution is mixed with a water-soluble polymer before injection into the reservoir, the amount of water-soluble polymer being 0.02-0.2% of the total weight of the mixture.