RU2416023C1 - Procedure for development of hydrocarbon deposit - Google Patents

Abstract

FIELD: oil and gas production. ^ SUBSTANCE: procedure consists in pumping associated gas through pressure wells into horizon of lost circulation corresponding to horizon with residual oil and/or gas and/or formation water; said horizon is located below pay. There is maintained initial pressure at pumping associated gas, which is as high, as pressure of exposure of natural fissures present in the lost circulation horizon. There are recorded change of volumes and pressure of pumped associated gas. Upon stabilisation of pumping modes, there is made a conclusion on effect of associated gas pumped to the pay. In the pay pressure is boosted to overcome an initial value required for development of the deposit. If pumped associated gas does not effect the pay, then this gas is pumped into additional receiving reservoirs. In case of failure of the above described effect from pumped associated gas, there is used the reservoir for temporary storage of associated gas. ^ EFFECT: increased efficiency of oil deposit development and ecological safety in first years of operation. ^ 2 cl

Description

The invention relates to the oil and gas industry and can be used for the return of associated gas (GHG), associated formation water and industrial effluents (industrial waste water) generated during the development and operation of oil or gas condensate fields.

There is a method of injecting gas into productive formations to increase the extraction of liquid hydrocarbons (cycling process) (see Guidelines for the extraction, transport and processing of natural gas. D.L. Katz and other Publishing House "NEDRA". 1965).

However, this method is not economically advantageous to use in small oil and gas fields of complex geological structure. In such fields, oil, condensate and gas reserves are determined with large errors. The lithological heterogeneity of the reservoirs, fracturing, tectonic disturbances and other features of the field are unknown. It is known that the cycling process requires significant additional costs and is used in large, well-studied gas condensate fields. In our country, the cycling process has not been implemented at any gas condensate field. One of the reasons is the high cost of the process of conservation of dry gas reserves (see. Improving the technology for developing oil and gas fields. / Under the editorship of S.N. Zakirov. - M.: Grail. - 2000. - 643 p.).

There is a method of injecting water and gas into productive formations to increase oil recovery in the primary process or in the form of a secondary process in order to obtain additional oil from the reservoir after it is practically no longer extracted during natural operation (see Production Guide, transport and processing of natural gas. D.L. Katz et al. Publishing House "NEDRA". 1965).

This method is also not economically advantageous to use in small oil and gas fields of complex geological structure. It is known that the injection of water and gas requires significant additional costs, including drilling additional wells. Therefore, this method can be used in large oil fields.

In addition, productive formations may not accept injected formation water.

A known method for the development of oil deposits (see RF patent for the invention No. 2355882, IPC ЕВВ 43/20). The method can be used in the return of associated formation water and industrial effluents (industrial waste) generated during the development and operation of oil or gas fields. In the method, the sole of the reservoir is determined. Associated formation water is pumped through injection wells into a water intake reservoir located below the bottom of the productive reservoir of the oil reservoir. Record the change in volumes and pressure of injected associated formation water. After stabilization of the injection regimes, a pressure is created in the reservoir that exceeds its initial pressure.

In the absence of the necessary impact on the reservoir, additional research and work with the reservoir are carried out.

Industrial wastewater or a mixture thereof with associated formation water is pumped into a water intake formation located below the water intake formation into which associated formation water is pumped.

In the method mentioned above, the absorbing horizon for burial sites of industrial waste can not always provide the necessary impact on the reservoir with small volumes of associated formation water, which is observed in the first years of field development.

In the early years of field development, a large amount of associated gas (GHG) can be produced, which, due to the lack of use methods, is in many cases flared, polluting the environment.

The problem to which the invention is directed is to increase the efficiency of oil field development and environmental safety in the early years of oil field development, in the presence of significant volumes of associated gas (GHG).

The technical result is an increase in the degree of oil and gas condensate recovery and the possibility of temporary storage of associated gas.

The problem is solved in that in the method for developing hydrocarbon deposits, associated gas is pumped through injection wells into an absorbing horizon, which is used as a reservoir containing residual oil and / or gas and / or produced water and located below the reservoir, maintain the initial injection pressure associated gas is not lower than the opening pressure of natural cracks in the absorbing horizon. In the method, the change in volumes and pressure of the injected associated gas is recorded, and after stabilization of the injection regimes, a conclusion is drawn about the effect of the associated gas injection on the reservoir. Create a pressure in the reservoir that exceeds its initial value for developing the reservoir, in the absence of the influence of the associated gas injection on the reservoir, the associated gas is pumped into the additional receiving reservoirs, in the absence of the influence of the associated gas injection in the latter case, the reservoir is used for temporary storage of associated gas

Additionally, industrial drains or their mixture with associated formation water, located below the receiving formation, into which associated gas is pumped, are pumped into the water intake formation.

Determining the bottom of a productive formation allows you to install a formation with the desired properties (porosity, permeability, thickness, injectivity, etc.).

In the absence of a receiving formation with the necessary properties, the selection of receiving layers with the necessary properties is continued.

In this case, special work is carried out with the reservoir to increase its injectivity and select a reservoir with the necessary properties above the reservoir and below a reliable tire.

The injection of associated gas through injection wells into a receiving formation located below the bottom of the productive formation of an oil or gas-oil reservoir, and into other receiving reservoirs increases environmental safety due to the reliable isolation of the receiving reservoir used to return the GHG, the producing reservoir and the tire from the surface. At the same time, observation and production wells in the reservoir allow additional control over the process of returning associated gas to the reservoir.

Registration of changes in volumes and pressure of injected associated gas serves to fix the moment of possible overflow of associated gas below and above the receiving formation. If there is overflow, that is, with stabilization of the volumes and pressure of the associated gas injected, we can begin to develop an oil or gas condensate reservoir.

The creation of a pressure in the reservoir (pressure) exceeding its initial value, increases oil recovery and condensate production from reservoirs.

An advantageous result is the placement and temporary storage of significant volumes of associated gas within the developed field. This increases the pressure in the reservoir, which allows to increase the selection of oil, gas and condensate from it. In addition, the injection of associated gas and produced water prevents the spread of industrial waste water, which is pumped into the water intake reservoir located below the receiving reservoirs into which the associated gas is pumped. Injected associated gas creates an additional barrier and prevents industrial waste from entering the reservoir and onto the surface.

The method is as follows.

Equip one or more injection wells associated with receiving formations at an oil or gas field.

Separate collection of associated gas of produced water and industrial waste is carried out. Allocate in the context of the reservoir with industrial or residual oil reserves. Then, several receiving formations with the necessary properties: maximum porosity, thickness and permeability are identified below and above the reservoir.

Associated gas is pumped through the injection well and the injection / observation well into the receiving reservoirs with maximum porosity and permeability, located below and above the bottom of the reservoir. Record changes in volumes and pressure of injected associated formation water.

In the absence of flow of injected associated gas from the receiving strata, additional studies are carried out. In this case, receiving formations are injected into the reservoir located in close proximity to the reservoir, in addition, special work is carried out with the reservoir to increase the volume of gas injected into it.

With increasing pressure in the observation / production wells included in the production fund, a decision is made to increase oil production in existing wells or to introduce new wells into development.

For the injection of production wastewater, which consists of a mixture of associated formation water and industrial wastewater, the lowest water intake reservoir is used.

Claims (2)

1. A method of developing a hydrocarbon reservoir, characterized in that associated gas is pumped through injection wells into an absorbing horizon, which is used as a reservoir containing residual oil and / or gas and / or produced water and located below the reservoir, maintain the initial pressure associated gas injections not lower than the opening pressure of natural cracks present in the absorbing horizon, the change in volumes and pressure of the injected associated gas is recorded even after stabilization of the injection regimes and make a conclusion about the effect of the associated gas injection on the reservoir, create a pressure in the reservoir that exceeds its initial value for developing the reservoir, in the absence of the influence of the associated gas injection on the reservoir, the associated gas is pumped into additional receiving reservoirs, in the absence of the effect of the associated gas injection in in the latter case, a formation is used for temporary storage of associated gas. 2. The method according to claim 1, characterized in that, in addition, industrial wastewater is pumped into the water intake reservoir or a mixture thereof with associated formation water located below the receiving formation into which the associated gas is pumped.