RU2597395C1 - Investigation method of hydrocarbon deposits - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: invention relates to oil industry and can be used in development of oil deposits by thermal methods, particularly in organization of in-situ combustion (HSV). This method is realized by pumping to injection well together with expelling and/or oxygen-containing agent of tracer agent which changes chemical formula at required temperature, but keeps safe tracer properties and recordings of concentration of initial and transformed tracer agents in producing wells. For this purpose, at least one tracer agent is pumped at least in one injection well, which changes the chemical formula at required temperature, but retains tracer properties and registers concentration of initial and transformed tracer agents separately at least in one production well. After that, according to the ratio of initial and transformed tracer agents in well production temperature and dimensions of the zone of thermal effect or combustion are estimated.

EFFECT: increase of information about studied object of development, determination of temperature in the zone of thermal action,particularly in combustion zone at HSV to optimize the mode of injection of the oxidant and/or heat carrier and/or displacing agent into layer.

5 cl, 2 tbl, 3 dwg

Description

The invention relates to the oil industry and can find application in the development of oil deposits by thermal methods, in particular in the organization of in-situ combustion (HSV).

A known method (analogue) of determining the nature of the fluid filtration in the reservoir (SU 1473405 A1, 01/30/1994), based on the injection of the indicator into the injection well and its subsequent determination in the products taken from the production well, to exclude the destruction of the indicator and its sorption by rock as of the indicator, fluorochromes (various stains) that are resistant to formation fluid (biomass of microorganisms) previously introduced into the cells of microorganisms are pumped into the injection well.

A known method (analog) of monitoring the development of multilayer oil fields (SU 1730442 A1, 04/30/1992), including sampling the produced fluid from each oil reservoir and well production, then the content of chemical components is determined in the aqueous phase of the samples, water solutions are pumped into the oil reservoirs alternately of the same chemical components (for example, solutions of halogens and nitrates of alkali metals) and by the change in their concentration in samples of well production, the filtration characteristics of oil-bearing formations and their tnositelnom water production rate.

A known method (prototype) for studying liquid-phase dynamic processes in formations (oil and aquifers) with abnormally low pressure (RU 2164599 C1, 03/27/2001), including the use of indicators of several colors in the form of a liquid suspension of microgranules, consisting of a mixture of polycondensation resin and organic luminescent substance , each of which (indicator of the same color) is pumped into the corresponding injection well and a sample is taken from the observation wells, determining the concentration of the indicator of each color, then find ennomu plurality of time values for each color change of the indicator concentration in the near-wellbore capacitively determine its filtration properties and direction of the liquid-phase flows.

The disadvantage of these methods is the thermal destruction of tracers when applying thermal methods, which significantly reduces their information content in HSV.

The proposed solution allows not only to eliminate this drawback, but also to obtain fundamentally new information - an estimate of the temperature in the heat-affected zone in the oil reservoir, in particular, an assessment of the temperature in the combustion zone during HSV.

The aim of the invention is to increase the efficiency of hydrocarbon field development using thermal methods, which is achieved by optimizing the injection modes of the oxidizing agent and / or coolant and / or displacing agent into the reservoir based on determining the temperature in the heat affected zone, in particular in the combustion zone during HSV and increasing informativeness about the studied reservoir.

SUMMARY OF THE INVENTION

The essence of the proposed method lies in the fact that at least one injection well is injected into at least one injection well together with an injected agent, changing the chemical structure (transforming) at the required temperature. The concentration of the separately starting and transformed tracing agent in at least one producing well is recorded, after which the temperature and dimensions of the heat or combustion zone are estimated by the ratio of the starting and transformed tracing agents in the wells

To implement the method, the following separate technical solutions can be additionally used:

when an oxygen-containing mixture is pumped into a deposit, studies are carried out periodically or regularly for the presence of a transformed tracer in the products of at least one producing well, and when the latter appears, make a conclusion about the beginning of the combustion process;

at least one well in at least one formation or interlayer simultaneously injected at least two tracer agents that change the chemical structure (transforming) at two different temperatures;

the transformation temperature of the at least one tracer agent is higher than the possible temperature in the heating or combustion zone;

the transformation temperature of at least one tracer is lower than the possible temperature in the heating or combustion zone, but above the initial formation temperature.

As tracing agents in the proposed method can be used, for example, various chemical and radioactive reservoir tracers, indicators or markers, both artificial, specially designed for these purposes, and naturally occurring in nature [1].

The essential features of the method are the injection of at least one injection well together with the injected tracer agent in the required concentration.

The following features of the invention are attributed by the authors to private options for implementing the method described in the independent claim:

registration of the concentration of the tracer agent in at least one producing well;

injection of at least one tracer agent that changes the chemical structure (transforming) at the required temperature;

registration of the concentration of separately the source and transformed tracer agent in at least one production well;

assessment of the temperature and size of the heat or combustion zone by the ratio of the initial and transformed tracing agents in the production of wells;

injection of oxygen-containing mixture into the reservoir;

occasional or regular testing for the presence of a transformed tracer in the products of at least one producing well;

a conclusion about the beginning of the combustion process when a transformed tracing agent appears in the production of wells;

the simultaneous injection of at least one well in at least one layer or layer of at least two tracer agents that change the chemical structure (transforming) at two different temperatures;

the transformation temperature of the at least one tracer agent may be higher than the possible temperature in the heating or combustion zone;

the transformation temperature of at least one tracer agent may be lower than the possible temperature in the heating or combustion zone, but above the initial reservoir temperature.

The invention is illustrated in FIG. 1, which schematically shows an example implementation of the proposed method, FIG. 2 with a proportional diagram in a mixture of tracers shown in table 1 of the description, and FIG. 3 with a proportion chart in the mixture of tracers shown in table 2.

Examples of the implementation of the proposed method.

Example 1. Using one transforming tracer.

Figure 1 schematically shows an example implementation of the proposed method. Air injection and tracer injection are shown, capable of changing the chemical structure (transforming) at a temperature in the combustion zone (250 ° C) into one injection well. Registration of the initial and transformed tracing agents is carried out through two production wells. It has been shown that under certain conditions, a combustion zone with a high temperature of 250-450 ° C is formed in the formation, in which oxidative reactions and cracking of hydrocarbons occur.

Table 1 shows the proportion of the initial and transformed tracers in the initial mixture of tracers injected into the well, as well as three options for different proportions of tracers recorded in production wells. The initial temperature of the formation is 70 ° C, the transformation temperature of the tracer is 250 ° C.

In FIG. 2 shows a proportional diagram in a mixture of tracers, presented in table 1.

Option 1 corresponds to the case when only the source tracer appeared in the production well. Obviously, the temperature in the formation does not exceed the transformation temperature of the tracer, that is, less than 250 ° C.

Option 2 corresponds to the case when it was possible to register practically only the transformed tracer in the production well, the proportion of the initial tracer is insignificant. Obviously, the temperature in the reservoir exceeds the transformation temperature of the tracer, that is, more than 250 ° C.

Option 3 corresponds to the case when the proportion of the source and transformed tracers in their mixture in the production well are comparable. Two different explanations are possible here: 1) the temperature in the combustion zone is close to 250 ° C; 2) the combustion zone has arisen only in part of the strata, interlayers or cracks, in the remaining parts of the combustion deposit is not yet.

Example 2. The use of several transforming tracers.

Table 2 shows the proportion of the initial and transformed tracers in the initial mixture of tracers injected into the well, as well as three options for different proportions of tracers recorded in production wells. The initial temperature of the reservoir is 70 ° C.

In FIG. 3 shows a proportional diagram in a mixture of tracers, presented in table 2.

Option 1 corresponds to the case when only the initial tracers appeared in the production well. Obviously, the temperature in the formation does not exceed the transformation temperature of the first tracer, that is, less than 200 ° C.

Option 2 corresponds to the case when the first transformed tracer and the second initial tracer are registered in the production well, the share of the first initial tracer being insignificant and the second transformed at all. Obviously, the temperature in the formation exceeds the transformation temperature of the first tracer, but less than the transformation temperature of the second tracer. Accordingly, the temperature in the heated zone of the formation is from 200 ° C to 300 ° C.

Option 3 corresponds to the case when among the registered tracers there are practically only transformed ones. Therefore, the temperature in the heated zone of the formation exceeds 300 ° C.

Information sources

1. Sokolovsky E.V., Soloviev GB, Trenchikov Yu.I. Indicator methods for the study of oil reservoirs. - M .: Nedra, 1986. - 157 p.

Claims (5)

1. The method of researching oil fields, which consists in injecting at least one injection well together with the injected tracer agent in the required concentration, changing the chemical structure at a known temperature, and registering its concentration in production wells, characterized in that the concentration is recorded separately at least one source and transformed tracer in at least one production well, after which the ratio of the source and the transformed With the help of tracing agents in well production, the temperature and dimensions of the heat-affected or combustion zone are estimated. 2. The method according to p. 1, characterized in that when the oxygen-containing mixture is injected into the reservoir, studies are carried out periodically or regularly for the presence of a transformed tracer in the products of at least one producing well, and when the latter appears, a conclusion is made about the beginning of the combustion process. 3. The method according to p. 1, characterized in that at least two tracer agents that change the chemical structure (transforming) at two different temperatures are simultaneously injected into at least one well in at least one formation or interlayer. 4. The method according to p. 3, characterized in that the temperature of the transformation of at least one tracing agent is higher than the possible temperature in the heating or combustion zone. 5. The method according to any one of paragraphs. 1-4, characterized in that the temperature of the transformation of at least one tracer agent below the possible temperature in the heating or combustion zone, but above the initial reservoir temperature.

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