SU857451A1 - Method of determining initial water-encroachement of gas well - Google Patents

Description

(54) METHOD FOR DETERMINING THE INITIAL FLUID OF A GAS WELL

I

The invention relates to gas production, its industry and can be used in the development and exploitation of gas fields.

There is a method of monitoring the watering of gas and gas condensate wells, including monitoring the change in the content of chlorine ion, the content of which increases as the formation water 1 arrives.

However, this method does not make it possible to determine the beginning and degree of watering, and it can only be judged by whether a gas well is watering or not.

There is also known a method for determining the initial water-flooding of a gas well by determining the chlorine content in the separated water 2.

The disadvantage of this method is the inability to control the degree of flooding.

The purpose of the invention is the possibility of monitoring the degree of flooding.

This goal is achieved by additionally conducting a periodic determination of the content of the hydrocarbonation and judging the reduction of the ratio of the hydrocarbonation to the chlorinion to irrigate the well.

The basis of the proposed method is the inverse relationship between the ratio

 ions in the separated water and its menralization in the process of watering, due to the relatively high content of bicarbonate ions and an insignificant content of chlorine ions in

) Q water condensate and, conversely, low content of hydrocarbonation and a high content of hlorion in highly mineralized formation water.

To determine the degree of watering, 15 wells take a sample of the separated water and determine the content of the hydrocarbonation in it by titration with 0.05 N hydrochloric acid solution in the presence of methyl orange indicator and the content of chlorion by titration with 0.05 N solution of sodium nitrate rib in the presence of potassium chromate soda indicator, then set the ratio of hydrocarbon to chlorion.

Example 1. At the Uchkyr field, a sample of water condensate was taken from well 5 in a volume of 50 ml, and the hydrocarbonation content was determined by titration of 0.05N HC1 in the amount of 3.5 ml in the presence of a methyl orange indicator. Received 0,2136 g / l bicarbonate.

In the same volume, a sample of water condensate was taken and the content of chlorion was determined by titration of a 0.05N AgNOj solution in the amount of 2.48 ml in the presence of potassium chromic acid. Received 0,088 g / l of hlorioia. „-

-Iwe ratio

The obtained value of the ratio shows that the well is not watering, i.e. well is working normally.

Example 2. After some time, a sample of water condensate in the same volume was taken from the same well. In the selected sample of water condensate, the content of hydrocarbonation was determined by titration of a 0.05N solution of HC1 in an amount of 1.2 ml in the presence of a methyl orange indicator. 0.0732 g / l of hydrocarbonation was obtained.

Then a sample was taken for chlorine content. Received 4,1174 g / l of chlorine. - 0, W

Ratio This ratio value,%, corresponds to the initial water-cut of the well.

Example 3. At the Achak field, a sample of 50 ml of water condensate was taken from well 202, and the hydrocarbonation content was determined by titration of a 0.05N solution of HC in the presence of methyl orange. Received 0.1221 g / l bicarbonation.

Then, the content of chlornone in the sample of water condensate of the same volume was determined. Received 3,050 g / l of chlorine.

You are the ratio of the NSO

 ., i 050

The resulting ratio corresponds to the initial watering of the well.

Example 4. In the selected sample of water condensate from the same well 202 from 05.03.69, the content of bicarbonate was determined. The content of hydrocarbonation was determined by titration of a 0.05N solution of HC in the presence of methyl orange indicator. Received 0,1135 g / l bicarbonation.

The method described above determined the content of chlorion in a sample of water condensate from the same well 202. 0.504 g / l of chlorinion was obtained.

The calculated ratio is 0.1135, - 022

"0,504- -ucoi

The resulting value of the ratio corresponds to the normal operation of the well. Based on the data processing of about 3000 analyzes of water condensate, a definitive table has been compiled, with the help of which, however, the established ratios control the degree of flooding of the well 0 with reservoir waters of various salinity.

1.0 0.2-4 and 0.5 1.0 more

1.0-5.0 0.03-0.2 0.5-2.0 1.0-0.1

5, 0 0.01-0.03 2.0-5.0 0.1-0.03 or more and more

High - 0.0001-0.01 High-0.001-0.03

mineralo-non-isolized

condensed condensate

DensatPlastova

Plastova water

water

The proposed method of determining a gas well watering results in a significant economic effect due to the possibility of timely determining the start of watering and its degree, controlling the degree of watering, and timely watering prevention that prolongs the normal operation time of gas wells.

Claims (2)

1. Petrenko DI and others. Control over the watering of gas condensate wells by observing the salinity of formation waters. “Gas business, VNIIOENG, 1966, No. 2. 2. Markov, O. N. et al. Using the hydrochemical method of monitoring the operation of a gas well using the example of the Gazli field. “Gas business, VNIIOENG 1967, No. 8 (prototype).