RU2265116C2 - Oil production composition - Google Patents

Abstract

FIELD: oil production industry, particularly to develop oil wells, to isolate formation during water-bearing oil deposit development.

SUBSTANCE: oil production composition comprises gypsum containing material and hydrocarbon liquid taken in the proportion of 1:1-2.5. The composition is treated with solution of hydrochloric or sulfuric acid taken with ratio of 1:1-5 correspondingly. Oil-water emulsion or crude oil may be used as the hydrocarbon liquid. Semihydrate gypsum, high-strength gypsum, phosphogypsum or dry plaster may be utilized as the gypsum containing material. The composition may additionally have setting retarder, namely bone glue taken in amount of 0.015-0.3 parts by weight.

EFFECT: increased oil output, improved cementing properties along with water influx limiting, optimization of setting time regardless of formation water pH level and reduced cost of grouting composition.

8 cl, 3 tbl

Description

The invention relates to the oil industry, in particular to the field of oil well development, and can be used to isolate the reservoir during the development of a waterlogged oil deposit, thereby increasing oil recovery.

Known composition for oil production (see Danyushevsky BC, Aliev PM, Tolstoy IF Reference manual for cementing materials. 2 ed. Perer. And add. - M .: Nedra, 1987. 373 pp.) Containing gypsum, water and various additives.

The disadvantages of this composition are the short setting time and the need for additional introduction of various additives - moderators of the curing process. In addition, gypsum grouting compositions have low water resistance both at room and at high (80-90 ° C) temperatures, which is unacceptable under the conditions of operation of oil wells due to the effect of retamping.

Also known is a composition for oil production (see RF Patent No. 2139985, IPC E 21 B 33/138) containing an astringent and modified surfactant hydrocarbon fluid, while the binder contains gypsum-alumina or tensile cement.

The disadvantage of this composition is the complete suppression of not only water inflow, but also oil inflow (oil condensate inflow). The setting time is limited from 2 hours 30 minutes (start of setting) to 8 hours 15 minutes (end of setting), which may be insufficient in the conditions of operation of oil producing wells (it may take less than 2 hours 30 minutes and more than 8 hours 15 minutes).

Closest to the proposed is a composition for oil production, consisting of gypsum-containing material and a hydrocarbon liquid - water-oil emulsion (see US patent No. 2887159, publ. 05.15.1989).

The objective of the present invention is to improve the plugging properties while limiting water inflow, optimizing the setting time regardless of the pH of the formation water and reducing the cost of grouting compositions by reducing the number of components to a minimum amount.

The problem is solved due to the fact that the composition for oil production, including gypsum-containing material and hydrocarbon liquid, contains these components in a ratio, parts by weight 1: 1-2.5 and treated with a solution of hydrochloric or sulfuric acid in a ratio of 1: 1-5, respectively. As a hydrocarbon liquid, a water-in-oil emulsion or crude oil may be used. As gypsum-containing material can be used gypsum hemihydrate, for example high-strength gypsum grade G 5-7 or phosphogypsum, or dry plaster mix. The composition may additionally contain a retarder - bone glue 0.015-0.3 wt. hours

As can be seen from table No. 1, the setting time of the composition depends on what material is used as a hydrocarbon fluid or gypsum-containing material, as well as on the presence or absence of a setting retarder.

Tab. No. 1 No. p / p The composition of the grouting material, wt.% Setting time, h-min Start end 1 Gypsum (100 g) + Water (50 g) 8 min 12 min 2 Gypsum (100 g) + Oil / Yakush / (180 g) 3 h viscous mass 3 Gypsum (100 g) + VNE / Cap / (100 g) 4 min 13 min 4 Gypsum (100 g) + VNE / Cap / (135 g) 5 minutes 12 min 5 Gypsum (100 g) + VNE / Yakush / (135 g) 14 min 21 min 6 Gypsum (100 g) + VNE / Yakush / (225 g) 3-00 viscous mass 7 Gypsum (100 g) + VNE / Yakush / (225 g) 3-00 more than 8 hours 8 Gypsum (100 g) + VNE / Yakush / (180 g) + KK (03%) 8-00 12-00 nine Gypsum (100 g) + VNE / Yakush / (180 g) + KK (0.3%) 8-00 14-00 10 Gypsum (100 g) + VNE / Yakush / (225 g) + KK (03%) 8-00 12-00 eleven GS (100 g) + VNE / Yakush / (225 g) 3-30 more than 6-00 12 GCC (100 g) + VNE / Yakush / (225 g) more than 8-00 14-00

Where:

VNE - water-oil emulsion,

/ Yakush / - oil of the Yakushkinsky field,

/ Cap / - oil of the Saratov field,

GS - dry plaster gypsum mixture,

GCC - dry stucco gypsum-cement mixture,

KK - bone (carpentry) glue.

The results of processing the composition for oil production with acid solutions are shown in table No. 2.

Table No. 2 Oil hardeners of various deposits Sulfuric Acid Treatment Hydrochloric acid treatment H ₂ SO ₄ : H ₂ O = 1: 1 H ₂ SO ₄ :
H ₂ O = 1: 3 H ₂ SO ₄ : H ₂ O = 1: 5 HCl: H ₂ O = 1: 1 HCl: H ₂ O = 1: 3 HCl:
H ₂ O =
1: 5 Exposure time, min fifteen 60 fifteen 60 24 h fifteen 60 fifteen 60 24 h Saratov field 7.6 16.6 5.2 20.6 8.3 5,0 22.1 7.4 16,0 22.8 Yakushkinsky field 2.1 8.3 6.4 6.3 5,0 5.2 18.2 8.4 15.8 24.4

The grouting compositions were studied on a reservoir model (sandstones) to study the effect of the reagent composition on reducing the water and oil permeability of the rock.

The results of the waterproofing properties of the reagent compositions on the reservoir models are shown in table No. 3

Table number 3 Reagent Composition Initial permeability of the reservoir model
K _in, um ²
(md) Initial pressure gradient of water filtration,
G _in , MPa / cm The permeability of the reservoir model after exposure to the reagent K _in1 ,
μm ² ,
(md) Pressure gradient of water filtration after exposure to reagent G _in1 , MPa / cm conclusions 1 2 3 4 5 6 7 Gypsum (300 g) + Water-oil emulsion
this Composition
Number 4 0.26 (260) In the preparation of the reagent composition, a highly viscous solution was formed, which rather quickly turned into a solid lumpy mass                                     VNE (300 ml) VNE (on Cap. Nef.) 1n: 1v Gypsum (300 g) + VNE (300 ml) (Yakushkinskaya) 2n: 3c Composition
Number 5 0.2666 (266.6) 0.0104 0 Gypsum (300 g) + Retarder (600 mg) + H _z O (150 ml) Composition No. 6 1,416 (1,416) 0.0059 0.4295 (429.5) 0.0061 The permeability of the reservoir model decreased by 3.3 times Dry stucco gypsum mixture (300 g) + H ₂ O (150 ml) Composition
Number 7 1,313 (1313) 0.0022 1,313 0.0022 The reagent in the reservoir model was not filtered, the composition is permeable Dry plaster cement
gypsum mixture (300 g) + H ₂ O (150 ml) Composition number 8 1.3 0.002 0,0007 (0.7) 0.68 The water permeability of the sample decreased by 1857 times

Claims (8)

1. The composition for oil production, including gypsum-containing material and hydrocarbon liquid, characterized in that it contains these components in a ratio of 1: 1-2.5, respectively, and is treated with a solution of hydrochloric or sulfuric acid in a ratio of 1: 1-5, respectively. 2. The composition according to p. 1, characterized in that as a hydrocarbon liquid using a water-in-oil emulsion. 3. The composition according to p. 1, characterized in that crude oil is used as the hydrocarbon liquid. 4. The composition according to p. 1, characterized in that gypsum hemihydrate is used as a gypsum-containing material. 5. The composition according to p. 4, characterized in that high-strength gypsum of grade G 5-7 is used as hemihydrate gypsum. 6. The composition according to p. 1, characterized in that phosphogypsum is used as a gypsum-containing material. 7. The composition according to p. 1, characterized in that as a gypsum-containing material use a dry plaster mixture. 8. The composition according to p. 1, characterized in that it further comprises a setting retarder - bone glue - 0.015-0.3 wt. hours