Oil production intensification technology

Acid compositions

A number of acid compositions have been developed to intensify oil production:

1. Composition SNPH-9010J for treatment of wells in carbonate reservoirs or terrigenous reservoirs with carbonate cement.

2. Composition SNPH-9021, SNPH-9030 for treatment of wells in terrigenous reservoirs.

Purpose

Intensification of oil production from low-permeability reservoirs; productivity restoration of highly productive wells which have reduced flow rate due to production induced factors; primary development of wells after drilling.

Advantages

• Low reaction rate with carbonate strata, providing deep penetration into the formation;
• High penetration into the pore space of the perforated part of the reservoir due to low interfacial tension at the acid composition – oil boundary;
• High solubility in relation to salts;
• High dispersing ability in relation to heavy oil sediments;
• Low corrosion activity;
• Effective clay dispersion.

Technology of acid solutions modification for OPZ wells

Multifunctional additive SNPH-8903A

Purpose

SNPH-8903 is used as a multifunctional complex additive in inhibited hydrochloric acid (possibly in mud acid) for its modification (refinement) and production of acid compositions.

Advantages

• Uniform penetration into high- and low-permeability rock zones, thereby increasing the radius of active drainage and involving the entire thickness of the formation in development;
• Prevention of the formation of emulsions and deposits upon contact of acid and reservoir fluids;
• Inhibition of precipitation in the formation after acid-rock reaction;
• Reagent consumption rate in hydrochloric acid from 2.5%;
• Self-preparation of an acidic mixture based on large-tonnage industrial raw materials-hydrochloric acid;
• Technologically advanced, convenient to use and store in the conditions of a well, workshop, base.

Iron ions stabilizer SNPH-8905

Purpose

SNPH-8905 is designed to stabilize iron ions in the technological processes of acid treatment of the bottomhole zone of the well

Advantages

• Low solidification temperature (below minus 50 °C);
• Prevention of precipitation and formation of persistent emulsions with reservoir fluids;
• Preservation of reservoir properties of a productive reservoir;
• Applicable in combination with other acidic components and in hydrochloric acid of various concentrations;
• Applies standard oilfield equipment.

The acid composition containing Reagent SNPH-8903 and Iron ions stabilizer SNPH-8905 possesses anticorrosive properties (the specific corrosion rate of steel St35 at 90° C in 12% HCl at concentrations of 25 g/dm3 SNPH-8903A and 13.5 g/dm3 SNPH-8905 is no more than 5 g/m2*h)

Acid corrosion inhibitor SNPH-8904

Purpose

SNPH-8904 is used in acid formulations to reduce their corrosive aggressiveness towards the metal surface.

Description

The corrosion inhibitor SNPH-8904 is applicable in acidic formulations with a high HCl content and at reservoir temperatures up to 120 °C. SNPH-8904 is effective in acidic formulations with a high HCl content and at reservoir temperatures up to 120 °C. The consumption rate of the SNPH-8904 inhibitor in hydrochloric acid, depending on the conditions of use (at high reservoir temperatures) from 1.5%.

Advantages

• Applicable at reservoir temperatures up to 120°C;
• Low solidification temperature (below minus 50 °C);
• Applicable in combination with other acidic components and in hydrochloric acid of various concentrations.

Modifier for facies- heterogeneous formations

Purpose

The SNPH-8909 grade A modifier is used in conjunction with an acid composition (AC). The products of the modifier’s interaction with hydrochloric acid contribute to the dissolution and removal of natural and anthropogenic colmatants of the porous medium, and the surfactants contained in the composition increase the wettability of the rock, slow down the reaction rate and prevent the formation of insoluble compounds.

Description

The technology involves structural deformations of clays under the influence of the SNPH-8909 + KK modifier complex.

The process is accompanied by an alteration in the mechanical properties of clays: their sorption capacity is lost, and their hydrophobic properties change.

The use of the technology prevents the precipitation of low-solubility compounds in a porous medium that occur during clay acid treatments.

Hydrophobing agent

Purpose

The SNPH-GF Hydrophobing agent of several grades is used as a part of process fluids for treatment of drilling fluids, solutions for killing wells, maximum preservation of filtration and capacitance properties of formation pay zone BHZ in order to intensify production and pick-up, eliminate and reduce costs associated with prolonged development and bringing wells to operation mode after changing underground equipment.

Description

The SNPH-GF Hydrophobing agent is a water-alcohol based liquid with a density of 800-1150 kg/m3 and a solidification temperature of up to -50oC. The effective dosage of Hydrophobing surfactant in the composition of process fluids can range from 0.1 to 3.0% by weight.

Advantages

The application of a Hydrophobing agent as part of the killing fluid makes it possible to eliminate or reduce the loss of operability of underground equipment associated with pumping the killing solution before receiving the pump or stopping its supply, it also makes it possible to reduce and eliminate a drop in well productivity after carrying out repairs.

SNPH-GF is transported by all modes of transport, except by air, in accordance with the rules of cargo transportation applicable to this type of transport.

Surfactants

Purpose

The technology of changing the wettability of the rock. SNPH-CM surfactants.

The use of hydrophobing agents makes it possible to increase oil production with lower unit costs by mobilizing fixed reserves and increasing oil recovery on a long-term basis.

The surfactant changes the wettability of the strata from a hydrophobic or mixed type to a maximally hydrophilic state.
Applies:

• at bottomholes treatment
• during hydraulic fracturing
• in the pressure maintenance system

Description

The SNPH-GF surfactant is a water and alcohol-based liquid with a density of 800-1150 kg/m3 and a solidification temperature up to -50oC. The effective dosage of surfactant in the composition of process fluids can range from 0.1 to 3.0% by weight.

Advantages

The use of a surfactant as part of the well-killing fluid makes it possible to eliminate or reduce the loss of operability of underground equipment associated with pumping the well-killing solution before receiving or stopping the pump supply and also makes it possible to reduce and eliminate a drop in well productivity after repairs.

SNPH-GF is transported by all modes of transport, except by air, in accordance with the rules of cargo transportation applicable to this type of transport.

The SNPH-CM surfactant reagent makes it possible to increase the displacement of oil and gas from the microporous space, where undisplaced oil remains during water injection, by increasing the effect of rock impregnation with a wetting displacing fluid.

It is used both independently and in combination with other reagents and traditional surfactants.

It increases displacement efficiency by 30% or more. Its selection is carried out in the laboratory.

SNPH-CM Technological additives to steam

SNPH-SM

Purpose

• Increase the displacement coefficient of high-viscosity oil during steam-thermal exposure
• Significantly reduce surface tension forces in the oil-steam system
• Reduce the amount of residual oil saturation behind the displacement front.

A steam additive based on SNPH-SM reagent is a specialized steam additive recommended for application in HNP huff and puff treatment and SAGD.

It allows to increase the adhesion of steam/ water in the area of the steam chamber to the rock, which is determined by the surface tension force (IFT) and the contact angle of wetting.

Independent studies show an increase in efficiency of up to 30% of oil displacement by steam with an additive based on the SNPH-CM additive compared with injection of pure steam.

Reagents for hydraulic fracture treatment

Liquid gelling agent SNPH-3800

Liquid gelling agent SNPH-3800 based on guar derivatives in a hydrocarbon solvent, is used as a gelling agent for hydraulic fracturing agent of the hydraulic fracturing fluid and a thickener in the process fluids to intensify well flow.

Liquid cross linker – SNPH-3801

SNPH-3801 is a borate-based liquid crosslinking agent used in guar-based fracturing fluids. The SNPH-3801 liquid cross linker is available in the grades: M (instantaneous effect) and H (low-temperature). It is intended for the preparation of crosslinked gels based on guar-containing gelling agents (e.g., SNPH-3800, SNPH-3830). The recommended concentration is from 0.5 to 5 liters/m3, depending on the gelling agent load and reservoir temperature.

Dry cross linker– SNPH-3802

The product is a dry cross linker based on boron-containing minerals with the addition of surfactants for the preparation of its suspension based on hydrocarbon solvents. It is used as a cross linker in water-based hydraulic fracturing fluids. The SNPH-3802 dry cross linker is available in grades: M (instantaneous effect) and Z (delayed effect).

Oxidizing destructor – SNPH-3803

The product is a persulfate destructor used to break polymer-borate bonds of hydraulic fracturing fluids based on guar or its derivatives (e.g. SNPH-3800, SNPH-3830). Working concentrations depend on reservoir conditions, injection volume and required gel stability and are usually 0.05 – 1.0 kg/m3.

Delayed Liquid cross linker – SNPH-3804

SNPH-8904 is a suspension delayed crosslinker and is intended for the preparation of crosslinked gels based on guar-containing gelling agents (e.g. SNPH-3800, SNPH-3830). The recommended concentration is from 2.0 to 10 l/m3, depending on the gelling agent load and reservoir temperature.

Biocide – SNPH-3810

SNPH-3810 is a soluble powdered bactericide (biocide) that is designed to control microorganisms in a wide range of oil and gas industry facilities, including water from artesian wells and surface sources before it is used for hydraulic fracturing purposes. For maximum effect, it is recommended to add it to the water before preparing the biopolymer solution.

Friction reducer – SNPH-3820

The reagent is a dispersion of a polymer with a high molecular weight. SNPH-3820 is used as an additive in the process fluids during drilling, hydraulic fracturing and well repair to improve lubricity and reduce the coefficient of friction.

Clay Stabilizer– SNPH-SG

Clay stabilizer is used as an additive to drilling mud and hydraulic fracturing fluids. Designed to prevent swelling and migration of clay particles.

Dry gelling agent SNPH-3830

SNPH-3830 is a powder of rapidly hydrating guar gum. SNPH-3830 is used as a gelling agent in hydraulic fracturing fluids and a thickener of process fluids for wells with a reservoir temperature of up to 80°C. It is available in the form of 2 grades: CC grade (semi-free flowing) and PS grade (increased flowing).

DEMULSIFIERS of the SNPH grade

The water-soluble demulsifier is pumped into the well as part of hydraulic fracturing process fluids and does not require additional preparation. It can be used in a wide range of temperatures. The content of the demulsifier in the finished composition can vary from 0.1 to 0.5%.

In 2019, pilot field tests were conducted on chemical treatment technology in conjunction with ultrasound exposure (acid injection and ultrasound treatment) at 2 wells of the Verey horizon (C2ver).

Well No. 5213 of the Staro-Kadeevskoye field	Well No. 5273 of the Staro-Kadeevskoye field
Mastering the transition to C2ver.	Intensification of inflow.
The planned flow rate has been reached by 100%. Reduction of work time during well development from 2-3 days to 10 hours.	Increase of the initial flow rate of the well by 80-100%.