CN105221134A - A kind of Fractured Gas Wells returns the method for discrimination that discharge opeing and formation water are formed - Google Patents

Abstract

The invention relates to a method for discriminating the composition of flowback fluid and formation water in a fracturing gas well. The gas test curve of a single gas well; and judge the liquid production type of each single gas well according to the change trend of the gas test curve of each single gas well; 2) When the liquid production type of a single gas well is flowback liquid only, the Liquid production composition of a single gas well; when the liquid production type of a single gas well is flowback fluid and formation water, a relationship model diagram of the chlorine content and liquid production of a single gas well is established according to the gas test curve of the single gas well; Discrimination of the composition of the flowback fluid and formation water of the gas well; 4) According to the composition of the flowback fluid and formation water of each single gas well, determine the composition of the flowback fluid and formation water of the fracturing gas well in the whole area. The present invention judges the liquid production composition of each single gas well, determines the severity of water production in gas wells and gas fields, helps to accurately grasp the impact of gas reservoir water production on development, and provides information for the formulation of specific gas well production work systems and water avoidance measures. Important basis and important reference.

Description

A Discrimination Method for Composition of Flowback Fluid and Formation Water in Fractured Gas Wells

technical field

The invention relates to a method for discriminating the composition of flowback fluid and formation water in a fracturing gas well, and belongs to the technical field of gas field production.

Background technique

Most of the gas fields in my country are ultra-low permeability gas fields with a permeability of less than 1 md, such as: Jingbian Gas Field, Liuyangbao Gas Field, Yulin Gas Field, Daniudi Gas Field, Guang'an Gas Field, etc. According to the origin of the existing gas fields, the effluent types can be roughly divided into three categories, namely primary formation water, external interlayer water and flowback fluid. Among them, primary formation water and external interlayer water belong to formation water. As shown in Table 1, primary formation water is further divided into primary edge and bottom water and primary retained water. The primary edge-bottom water is distributed near the gas-water boundary in the lower part of the structure, showing obvious water layer characteristics, high salinity, and the gas test curve shows a large amount of stable water production. Due to the poor physical properties of the reservoir and insufficient gas drainage during the accumulation process, the primary retained water remains in the formation, so there is no obvious pure water layer, high gas saturation, high salinity, and daily production on the gas test curve. The water volume is relatively stable. The external interlayer water is water from other layers, which is mainly related to the communication of faults and fractures. Because the interlayer water channeling will cause a large amount of water outflow from the gas well, the water production is stable at the beginning of the gas test, but after a period of time, the water production will suddenly increase. Its salinity is high and differs from that of primary formation water. The flowback fluid is part of the fracturing fluid and other working fluids remaining in the formation after the fracturing operation before putting into production. Its mineralization degree is low, and a large amount of water is produced in a short period of time at the beginning of the gas test, and then drops rapidly until the working fluid is flowed back.

Due to the defects of deep burial, strong diagenesis, and poor physical properties in the above-mentioned gas fields, the problem of low natural production capacity has occurred. In order to solve this problem, the existing technology mostly adopts fracturing measures to build production. However, in some gas reservoirs with water (such as Liuyangbao gas field), the fluid production is obvious in the gas testing stage after fracturing, and the composition of flowback fluid and formation water in the produced fluid is unclear. The establishment of the production construction work system has seriously interfered, which has an important impact on the deployment and efficient development of gas fields. However, there are still few reports at home and abroad on the judgment of flowback fluid and formation water composition of fracturing gas wells in ultra-low permeability gas reservoirs with water, so it is impossible to develop gas fields accurately and efficiently.

Table 1

Contents of the invention

In view of the above problems, the object of the present invention is to provide a simple, efficient and accurate method for discriminating the composition of flowback fluid and formation water in fracturing gas wells.

In order to achieve the above object, the present invention adopts the following technical solutions: a method for discriminating between the flowback fluid of a fracturing gas well and formation water, characterized in that:

1) Draw the gas test curve of each single gas well according to the on-site gas test dynamic data of each single gas well in the whole area of fracturing gas wells in the area to be tested, and judge the gas test curve of each single gas well according to the change trend of the gas test curve of each single gas well. The liquid production type of the gas well; the liquid production type of a single gas well includes two situations, one is only producing flowback fluid, and the other is producing flowback fluid and formation water;

2) Discriminate the liquid production composition of a single gas well:

When the fluid production type of a single gas well is flowback fluid only, it can be directly judged that the fluid production composition of the fractured gas well is all flowback fluid;

When the liquid production type of a single gas well is flowback fluid and formation water, the relationship model diagram of the chlorine content and liquid production of a single gas well is established according to the gas test curve of a single gas well, and the flowback of a single gas well is performed by standardizing the chlorine content Discrimination of produced liquid composition of liquid and formation water:

①According to the relationship model diagram of chlorine content and fluid production in a single gas well, determine the maximum value of chlorine content max(Cl), the minimum value of chlorine content min(Cl), and the Chloride content Cli, stable daily water production W _dp and cumulative liquid production F _p ;

② Determine the cumulative formation water production of a single gas well by standardizing the chlorine content:

${\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; p</span>}}\underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; no</span>}}{<span\; class="notranslate">\; \&Sigma;</span>}}\frac{\mathrm{<span\; class="notranslate">\; C</span>}\mathrm{<span\; class="notranslate">\; 1</span>}\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; m</span>}\mathrm{<span\; class="notranslate">\; i</span>}\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; C</span>}\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; m</span>}\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; C</span>}\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; min</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; C</span>}\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; ;</span>$

In the formula, W _p is the cumulative formation water production of a single gas well, Cli is the chlorine content of a single gas well when the production date is i, min(Cl) is the minimum value of the chlorine content of a single gas well, and max(Cl) is the The maximum value of chlorine root content; W _dp is the stable daily water production of a single gas well;

③ According to the cumulative formation water production of a single gas well, determine the cumulative flowback fluid production of a single gas well:

FB _p = F _p - W _p ;

In the formula, F _p is the accumulative fluid production of a single gas well, FB _p is the accumulative flowback fluid production of a single gas well, and W _p is the accumulative formation water production of a single gas well;

3) According to the cumulative output of flowback fluid and formation water of each single gas well, determine the composition of flowback fluid and formation water of a single gas well and the composition of flowback fluid and formation water of a fractured gas well in the whole area:

In the formula, RFB _{single gas} well is the flowback liquid ratio of single gas well, is the sum of cumulative flowback fluid production of fracturing gas wells in the whole area, ∑F _p is the sum of cumulative fluid production of fracturing gas wells in the whole area, RFB _{whole area} is the proportion of flowback fluid in the whole area;

4) According to the flowback fluid ratio of the single gas well and the flowback fluid ratio of the whole zone, the composition of the flowback fluid and formation water of the single gas well and the fractured gas well of the whole zone is confirmed.

The diagram of the relationship between the chloride content and the fluid production rate for the determination of the flowback fluid and formation water composition of a single gas well is as follows: when only flowback fluid is produced, the fluid production curve drops rapidly to 0 in a short time; When compared with formation water, the fluid production curve is a downward stable type, and the chlorine content curve is a stable upward type, which means that the gas well mainly produces flowback fluid at the initial stage of gas testing, and gradually transitions to a production formation as the chlorine content increases. water.

Because the present invention adopts the above technical scheme, it has the following advantages: 1. The present invention judges the liquid production composition of each single gas well, can implement the proportion of flowback liquid and formation water in the liquid production of a single gas well, and determine the gas well and formation water. The severity of water production in a gas field helps to accurately grasp the impact of water production in gas reservoirs on development, provides an important basis for the formulation of specific gas well production systems and water avoidance measures, and provides a basis for the selection of gas field blocks, well location deployment and production capacity evaluation. Provides important references. 2. Since the present invention calculates the flowback volume of the fracturing fluid and other working fluids of the gas well, it can judge the retention of the fracturing fluid and other working fluids in the formation, and can provide accurate basis and reference for subsequent gas well management . 3. Since the present invention can judge the formation water discharge time of the gas well according to the gas test curve, it can judge the cut-off time of the flowback liquid produced by the gas well in time, and provides a basis and reference for the production management of the gas well.

Description of drawings

Fig. 1 is a flow chart of the present invention;

Fig. 2 is the relation model diagram of the chloride radical content and liquid production rate of single gas well of the present invention;

Fig. 3 is the liquid production figure of the gas test curve of well A in the embodiment;

Fig. 4 is the liquid production figure of the gas test curve of well B in the embodiment;

Fig. 5 is the gas test curve chlorine radical content figure of B well in the embodiment;

Fig. 6 is the relation figure of the chloride root content and the liquid production rate of B well in the embodiment;

Fig. 7 is the composition diagram of flowback fluid and formation water of well B in the embodiment;

Fig. 8 is a composition diagram of the flowback fluid and formation water in the entire Liuyangbao Tai 2 gas reservoir in the embodiment.

detailed description

The present invention will be described in detail below in conjunction with the accompanying drawings and embodiments.

The present invention proposes a method for discriminating between the flowback fluid of a fracturing gas well and formation water, as shown in Figure 1, it comprises the following steps:

1) Draw the gas test curve of each single gas well according to the on-site gas test dynamic data of each single gas well in the whole area of fracturing gas wells in the area to be tested, and judge the gas test curve of each single gas well according to the change trend of the gas test curve of each single gas well. The liquid production type of gas well; the liquid production type of a single gas well includes two situations, one is only producing flowback fluid: the liquid production curve drops to 0 rapidly in a short time; the other is producing flowback fluid and formation water: liquid production The curve decreases in the early stage, and is stable and greater than 0 in the later stage; the corresponding chlorine radical curve rises in the early stage, and is stable in the later stage.

2) Discrimination of fluid production composition of a single gas well:

When the fluid production type of a single gas well is flowback fluid only, it can be directly judged that the fluid production composition of the fractured gas well is all flowback fluid.

When the liquid production type of a single gas well is flowback fluid and formation water, the relationship model diagram of the chlorine content and liquid production of a single gas well is established according to the gas test curve of a single gas well (as shown in Figure 2), and standardized by the chlorine content , to distinguish the flowback fluid of a single gas well and the fluid production composition of formation water:

①According to the relationship model diagram of chlorine content and fluid production in a single gas well, determine the maximum value of chlorine content max(Cl), the minimum value of chlorine content min(Cl), and the Chlorine content Cli, stable daily water production W _dp (water production after testing stability, close to formation water) and cumulative liquid production F _p ;

② Determine the cumulative formation water production of a single gas well by standardizing the chlorine content:

${\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; p</span>}}\underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; no</span>}}{<span\; class="notranslate">\; \&Sigma;</span>}}\frac{\mathrm{<span\; class="notranslate">\; C</span>}\mathrm{<span\; class="notranslate">\; 1</span>}\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; m</span>}\mathrm{<span\; class="notranslate">\; i</span>}\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; C</span>}\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; m</span>}\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; C</span>}\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; min</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; C</span>}\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; ;</span>$

In the formula, W _p is the cumulative formation water production of a single gas well, Cli is the chlorine content of a single gas well when the production date is i, min(Cl) is the minimum value of the chlorine content of a single gas well, and max(Cl) is the The maximum value of chlorine root content; W _dp is the stable daily water production of a single gas well;

③ According to the cumulative formation water production of a single gas well, determine the cumulative flowback fluid production of a single gas well:

FB _p = F _p - W _p ;

In the formula, F _p is the accumulative fluid production of a single gas well, FB _p is the accumulative flowback fluid production of a single gas well, and W _p is the accumulative formation water production of a single gas well;

3) According to the cumulative output of flowback fluid and formation water of each single gas well, determine the composition of flowback fluid and formation water of a single gas well and the composition of flowback fluid and formation water of a fractured gas well in the whole area:

In the formula, RFB _{single gas} well is the flowback fluid ratio of a single gas well, ∑FB _p is the sum of cumulative flowback fluid production of fractured gas wells in the whole area, ∑F _p is the sum of cumulative fluid production of fractured gas wells in the whole area, The _{whole area} of RFB is the proportion of flowback liquid in the whole area;

4) According to the flowback fluid ratio of the single gas well and the flowback fluid ratio of the whole zone, the composition of the flowback fluid and formation water of the single gas well and the fractured gas well of the whole zone is confirmed.

In the above embodiments, for the gas wells producing formation water, the liquid production curve is basically a downward stable type, and the chloride radical content curve is an obvious upward stable type. It reflects that the gas wells mainly produced flowback fluid at the initial stage of gas testing, and gradually transitioned to producing formation water as the content of chloride radicals increased.

The technical effects of the present invention will be further described below through a specific embodiment.

Example

It was applied in the study of water production mechanism of Liuyangbao Tai 2 gas reservoir, and the application results are as follows:

1) As shown in Figures 3-6, the gas test curves of gas wells A (Dingbei 26 Well) and B (Dingbei 10 Well) were first drawn in combination with the field gas test dynamic data. Change trend to judge the type of liquid production;

As shown in Fig. 3, the gas test curve of Well A was initially high in fluid production (daily fluid production>100m ³ /d), and then declined rapidly (daily fluid production fell to <5m ³ /d within 1 week). After a period of time, the stable daily fluid production drops to 0m ³ /d. It shows that the well mainly produces flowback fluid, and does not contain formation water.

As shown in Figs. 4 and 5, the liquid production curve in the gas test curve of Well B is a typical decreasing and stable type, and the chloride content curve is obviously rising and stable, and the correlation between the liquid production curve and the chlorine content is obvious. According to statistics, the daily fluid production of the well was 37m ³ /d and the chlorine content was 6300mg/L in the early stage of gas testing; as the gas testing time was prolonged, the stable daily fluid production was 3.6m ³ /d and the stable chlorine content was 20000mg/L in the later period. It shows that in the early stage of gas testing, the well mainly produces flowback fluid, and gradually transitions to mainly produces formation water as the content of chloride radicals increases.

2) Since the fluid production type of Well A is only flowback fluid, the composition of the fractured gas well can be directly identified. The fluid production type of Well B is flowback fluid and formation water, so it is necessary to draw a correlation diagram between chlorine content and fluid production in Well B according to the gas test stage curve of Well B (as shown in Figure 6), and through the chlorine Standardize the content to distinguish the flowback fluid and formation water composition of Well B. Among them, it can be seen from Fig. 6 that the liquid production curve of Well B is basically a declining and stable type, and the chloride root content is obviously rising and stable. The initial flowback liquid is mainly produced, and with the increase of the chloride root content, formation water is gradually produced. . And through the analysis of formation water wells, it is found that the relationship between chlorine radical content and liquid production rate of all gas wells producing formation water conforms to the pattern in Figure 2.

3) Discriminate the composition of flowback fluid and formation water in Well B:

①According to the relationship diagram of flowback fluid and chlorine root in well B, it can be determined that max(Cl)=19497mg/L, min(Cl)=6300mg/L, W _dp =3.6m ³ /d;

② Determine the cumulative formation water production of Well B by standardizing the chloride content:

${\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; p</span>}}\underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; no</span>}}{<span\; class="notranslate">\; \&Sigma;</span>}}\frac{\mathrm{<span\; class="notranslate">\; C</span>}\mathrm{<span\; class="notranslate">\; 1</span>}\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; m</span>}\mathrm{<span\; class="notranslate">\; i</span>}\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; C</span>}\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; m</span>}\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; C</span>}\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; min</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; C</span>}\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 98.6</span>}{\mathrm{<span\; class="notranslate">\; m</span>}}^{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; ;</span>$

③According to the cumulative formation water production, determine the cumulative flowback fluid production:

FB _p = F _p -W _p = 424.0-98.6 = 325.4m ³ /d;

④ According to the accumulated flowback fluid production, determine the flowback fluid ratio in single gas wells:

$\mathrm{<span\; class="notranslate">\; R</span>}\mathrm{<span\; class="notranslate">\; f</span>}\mathrm{<span\; class="notranslate">\; B</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; Facebook</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}}}{{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}}}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; 100</span>}\mathrm{<span\; class="notranslate">\; \%</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 325.4</span>}}{\mathrm{<span\; class="notranslate">\; 424.0</span>}}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; 100</span>}\mathrm{<span\; class="notranslate">\; \%</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 76.745</span>}\mathrm{<span\; class="notranslate">\; \%</span>}<span\; class="notranslate">\; ;</span>$

⑤According to the proportion of flowback fluid, confirm the fluid composition of Well B (as shown in Figure 7); the flowback fluid in the produced water of Well B accounts for 76.75%, and the formation water accounts for 23.26%.

4) Determine the composition of the flowback fluid and formation water of the fractured gas well in the Liuyangbao Tai 2 gas reservoir where Well B is located (as shown in Figure 8):

As shown in Table 2, from the calculation results, the proportion of flowback liquid in the produced water of gas wells in this area is relatively high, the proportion of flowback liquid in the produced water of the whole area is 76.8%, and the proportion of formation water is relatively small, with an average of 23.2%.

Table 2

Above-mentioned each embodiment is only for illustrating the present invention, wherein the structure of each component, connection mode etc. all can be changed to some extent, every equivalent conversion and improvement carried out on the basis of the technical solution of the present invention, all should not be excluded from the present invention. outside the scope of protection of the invention.

Claims (2)

1. Fractured Gas Wells returns the method for discrimination that discharge opeing and formation water are formed, and it is characterized in that:

1) according to the on-the-spot gas testing dynamic data of each single gas well in whole district's Fractured Gas Wells in district to be measured, draw the gas testing curve of each single gas well, judge the production fluid type of each single gas well according to the variation tendency of the gas testing curve of each single gas well; The production fluid type of single gas well comprises two kinds of situations, and one only produces to return discharge opeing, and another kind produces to return discharge opeing and formation water;

2) the production fluid formation of single gas well is differentiated:

When the production fluid type of single gas well returns discharge opeing for only producing, the production fluid formation that directly can determine this Fractured Gas Wells is all return discharge opeing;

When the production fluid type of single gas well is for returning discharge opeing and formation water, set up the relation schema figure of single gas well chloride content and Liquid output according to the gas testing curve of single gas well, by chloride content standardization, the production fluid returning discharge opeing and formation water carrying out single gas well forms and differentiates:

1. according to the relation schema figure of single gas well chloride content and Liquid output, determine the minimum value min (Cl) of the maximum value max (Cl) of the chloride content of gas testing stage single gas well, chloride content, chloride content Cli under arbitrary time, stablize water yield per day W _dpwith accumulative Liquid output F _p;

2. by chloride content standardized method, the accumulative formation water rate of single gas well is determined:

$W_p=W_{dp}\underset{i=1}{\overset{n}{\&Sigma;}}\frac{C1i-min\left(C1\right)}{max\left(C1\right)-min\left(C1\right)};$

In formula, W _pfor the accumulative formation water rate of single gas well, the chloride content that Cli is single gas well liquid loading date when being i, min (Cl) represents the minimum value of the chloride content of single gas well, the maximum value that max (Cl) is the chloride content of single gas well; W _dpfor the stable water yield per day of single gas well;

3. according to the accumulative formation water rate of single gas well, determine that the accumulative of single gas well returns discharge opeing output:

FB _p＝F _p-W _p；

In formula, F _pfor the accumulative Liquid output of single gas well, FB _pfor the accumulative of single gas well returns discharge opeing output, W _pfor the accumulative formation water rate of single gas well;

3) according to the accumulative output returning discharge opeing and formation water of each single gas well, the formation returning discharge opeing and formation water of single gas well and the formation returning discharge opeing and formation water of whole district's Fractured Gas Wells is determined:

In formula, RFB _{single gas well}discharge opeing ratio is returned, ∑ FB for single gas well _pfor the accumulative of whole district's Fractured Gas Wells returns discharge opeing output sum, ∑ F _pfor the accumulative Liquid output sum of whole district's Fractured Gas Wells, RFB _{the whole district}for the whole district returns discharge opeing ratio;

4) according to single gas well return discharge opeing ratio and the whole district returns discharge opeing ratio, and then the formation returning discharge opeing and formation water of confirmation form gas well and whole district's Fractured Gas Wells.

2. a kind of Fractured Gas Wells as claimed in claim 1 returns the method for discrimination that discharge opeing and formation water are formed, it is characterized in that: the relation schema figure carrying out the chloride content and Liquid output that return discharge opeing and the differentiation of formation water formation of single gas well is, when only product returns discharge opeing, in the production fluid curve short time, drop to 0 rapidly; When product returns discharge opeing and formation water, production fluid curve is decline stable type, and chloride content curve is rising stable type, namely represents that gas testing initial stage gas well returns discharge opeing to produce, and along with the rising of chloride content, progressively transition is for producing formation water.