SU747191A1 - Method of squeezing petroleum from seam - Google Patents

Abstract

1. METHOD FOR EXTRACTING OIL FROM THE PLASTE by successively pumping into it a rim of saline water and a micelle solution with an external aqueous phase, characterized in that, in order to increase the efficiency of the process of extrusion, the rim of saline water is pumped with a salt concentration that exceeds the concentration of saline micelle phase. 2. The method according to claim 1, wherein the mineral water is agitated with a salt concentration of between 4.6 and 51 times the concentration of the aqueous phase of the midcellular solution. (L

Description

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CD The invention relates to the field of oil-producing industry, in particular to methods of displacing oil from reservoirs. There is a known method of displacing oil from a reservoir by pumping a straight micellar solution into it. The method is applicable to formations whose water mineralization does not heat the mineralization of the aqueous phase of the micellar solution. A known method for displacing oil from a reservoir by successively pumping into it a rim of saline water and micellar dilution with an external aqueous phase. In this case, the concentration of salts of saline water is less than or equal to the concentration of salts of the aqueous phase of the micelle solution. The chain is to increase the efficiency of the displacement process. This goal is achieved by the fact that the rim of saline water is pumped with a salt concentration exceeding the salt concentration of the aqueous phase of the micellar solution from 4.6 to 51 times. The method is carried out in the following manner. A rim of mineralized water with a salt concentration exceeding the concentration of the injected then micellar solution with an external aqueous phase is pumped into the formation. At this time, the concentration of salts in the injected saline water exceeds the concentration of the aqueous phase of the micellar solution by 4.6–51 times. The state of direct micelle solution (PMR) in contact with water of various mineralization and with oil is well observed under static conditions. For this purpose, experiments were carried out according to the following procedure. . In a graduated cylinder of 50 ml capacity, pour water of a certain mineralization in a volume of 10 ml. Then, a direct micelle solution (30, ml) is carefully layered on the surface with a pipette and 10 ml of oil cj .8047 g / cm3 and, about 5.53hz, the micellar solution in these experiments had the following composition, wt%: Ammonium petroleum sulfonate equivalent weight 507 (in terms of the active substance) 3,6. Hydrocarbon (oil included in petroleum sulfonate) 8.0 Ammonium sulfate 2.4 Water tap 86.0 A micelle solution of this composition was prepared by mixing 80% of tap water with 20% petroleum sulfonate obtained in the Omsknefteorgsintez combination by neutralization ammonia sour tar by-product of the production of additives for oils C-300. The composition of this petroleum sulfonate is the following, wt%: Ammonium petroleum sulfonate. 18.0 Hydrocarbon (non-sulfonated oil) 40.3 Ammonium sulfate 12.0 Water. 29.7 Water of a certain mineralization was prepared by diluting the formation water of the Radaevskoye field with a total mineralization of 246.2 g / l with tap water in a volume ratio of 2: 1, 1: 1, 1: 2, 1:10, 1: 100. The formation water has 1.1633 g / cm and the following composition, g / l: SG150.40 1.18 i, 0.04 246.23 6 experiments were conducted in which the PMR was in contact with oil and water of various mineralization, starting from 246 to 2.4 g / l. The experiment was carried out at room temperature. Visually, in the cylinders, an active mixing of the PMR with oil and water of any mineralization was observed — intermediate layers formed between the phases. After 7-10 days, the phase mixing is completed. With this, the formation of three layers in the cylinders containing water by mineralization of the top 20 g / l was observed: the bottom (water) with a volume of 31-32 ml, the middle (reverse micelle-glar) with a volume of 6-7 ml and the top (oil) volume 10,53 11 ml. The boundary between the OMR and the oil layers is blurred, which indicates their limited miscibility under static conditions, and there is a clear interface between the OMR and the water phase. The composition of the resulting OMR is as follows, May.7,: Oil sulphonate 13.5-14.0 Hydrocarbon 33.0-36.0 Aqueous solution of salts50.0-54.0 In the experiment with water of the same salinity (2.4 g (l), as the mineralization of water in the PMR, two layers with a clear interface are observed: the bottom (diluted with IMP) with a volume of 38-39 ml and the top (oil) with a volume of 11-12 ml. Inversion of PMR to reverse MR in dynamic conditions proceeds much faster. A similar pattern of inversion of a direct micelle solution in the reverse was observed when PMR prepared on the basis of petroleum sulfonate with an average equivalent weight of 417 was in contact with water of the same salinity as in the case described above. The composition of the PMR on the basis of this phonate salt was as follows, wt. %: Oil sulphonate of average equivalent weight 4172.0 Hydrocarbon (oil, included in oil sulphonate) 1.2 Sodium sulphate 0.3 Water of total salinity 4.8 g / l. including Ca + Mg 0.21 g / l. The following examples illustrate the effectiveness of the proposed method for enhancing oil recovery using direct micelle solutions in extracting residual oil from a core simulating the third stage of development. Example 1. The petroleum extrusion capacity of a direct micelle solution based on petroleum sulfone of average equivalent 417 (the composition of the PMR is given above) was determined according to the following procedure. a layer 50 cm long and 1.1 cm in diameter, represented by quartz sand and having a porosity of 9Г4 36% and water permeability of 3.8 dar, is formed with formation water of the Radaevskoye field (its composition is shown above), then the water is displaced by three pore core volumes Alakaevo oil with a viscosity of 5.53 sps at 20 ° C and then the oil is displaced by tap water or water of other salinity (the ratio of Radaevsk water: tap water is 1: 0, 2: 1, 1: 1, 1: 2, 1:10, 1:50) to the maximum water cut of exiting liquid samples from the core. At the same time, the final oil displacement reaches 78-82%. Then in the kern village-. Successively, 5% of the pore volume of the direct micelle solution is pumped in, 50% of the pore volume of the aqueous solution of polyacrylamide with a viscosity of 7.0 cps, and then three pore volumes of tap water core. The experiments were carried out at room temperature (20-22 ° C). The obtained oil displacement data shows that the PMR practically does not displace oil from the core containing tap water or water that is close in terms of salinity to the water on which the TMR was prepared (4.8 g / l of salts). When mineralization of formation water in the core, for example, is 5 times higher than the mineralization of the TMR water (total salt content 2.4 g / l), the oil displacement of the direct micellar solution sharply increases to 65% and reaches a maximum value (90%) at total salt content in produced water is 120 g / l (content of Ca + Mg 5 g / liter). Good Oil-extrusion capacity of PMR (62 /) is also maintained when it is filtered through a core containing highly mineralized water (243 g / l) with a high content of alkaline, earth-soil cations (, 4 g / l). In commercial practice, the proposed The method of enhanced oil recovery is implemented in two versions, depending on the salinity of water pumped into the reservoir prior to the start of work on the WDT: direct injection of the WDT into the reservoir, if the reservoir is water-induced salinity more than 4,6-51 times higher than the salinity of the WRT water assumed to download; if the deposit is watered with low-mineralized water (for example, fresh water), then before the injection of the PMR it is necessary to introduce c. layer 1-5% of the volume

pores of saline water with a total salt content of at least 50 g / l (more accurately, the salt content is determined by preliminary laboratory tests). At the same time, saline water of 1 t is either on the high salinity brine water by diluting it with fresh water, or, if there is no reservoir water, by dissolving sodium chloride in fresh water.

The injection of the PMR is further promoted with a solution of a polymer (polyacrylamide, polysaccharide, etc.) on fresh water in a volume of 30-50% of the pore volume and then with low-mineralized water.

However, -IMP can be prepared in an aqueous polymer solution and then pumped into the formation.

With the intensification of well operations, the PMR can be forced into the well bottom zone and with fresh water if there is no water-soluble polymer. .

This method of using PMR is used at any stage of the development of oil fields.

The proposed method of increasing (2 oil recovery was tested for oil recovery is capable of (under field conditions during the processing of injection well No. 191 Radaevsky field, working under the injection of waste water with a total salt content of 260 g / l. In the well was pumped G1MR prepared from 2, 5 m of Omsk oil sulphonate (its composition is harvested above) and 7 m of fresh water, at 17 m perforation interval, the PMR was pushed into the bottomhole zone of the well with fresh water (11 m).

As a result of the processing

injection capacity of well No. 191 for wastewater increased from 316 to 500,550 m / day at the same injection pressure.

An approximate calculation of economic efficiency from at -1 times the estimated method while intensifying the work of 100 Injection wells shows savings of about 0.7 million rubles, while increasing

oil recovery at the third stage of development with the help of 10 thousand tons of Omsk sulphonate (in terms of 20% of the content of active substance) saving is about 2.0 million.

rubles with additional extracted tertiary oil 0.5 million m.

Claims (2)

. 1. METHOD FOR OIL EXTRACTION FROM THE STRING by sequentially injecting rims from mineralized water and a micellar solution with an external aqueous phase into it, characterized in that, in order to increase the efficiency of the displacement process, the rim from mineralized water is pumped with a salt concentration exceeding the concentration of salts of the aqueous phase micellar solution. 2. The method according to p. ^ Characterized in that the rim of mineralized water is pumped with a salt concentration of 4.6-51 times the concentration of water _. Q phase of micellar solution. <g