How to predict the flow rate of a gas well. Method for measuring the flow rate of a gas well. Calculation according to Dupuis
The main element of the water supply system is the water supply source. For autonomous systems in private households, dachas or farms wells or boreholes are used as sources. The principle of water supply is simple: the aquifer fills them with water, which is supplied to users using a pump. When the pump operates for a long time, no matter what its power, it cannot supply more water than the water carrier releases into the pipe.
Any source has a limiting volume of water that it can give to the consumer per unit of time.
Flow definitions
After drilling, the organization that carried out the work provides a test report, or a passport for the well, in which everything is entered required parameters. However, when drilling for households, contractors often enter approximate values into the passport.
You can double-check the accuracy of the information or calculate the flow rate of your well yourself.
Dynamics, statics and height of the water column
Before you start taking measurements, you need to understand what the static and dynamic water level in a well is, as well as the height of the water column in the well column. Measuring these parameters is necessary not only to calculate well productivity, but also to the right choice pumping unit for the water supply system.
- The static level is the height of the water column in the absence of water intake. Depends on in-situ pressure and is set during downtime (usually at least an hour);
- Dynamic Level – steady level water during water intake, that is, when the influx of liquid is equal to the outflow;
- Column height is the difference between the well depth and the static level.
Dynamics and statics are measured in meters from the ground, and the height of the column from the bottom of the well
You can take a measurement using:
- Electric level gauge;
- An electrode that makes contact when interacting with water;
- An ordinary weight tied to a rope.
Measurement using a signaling electrode Determining pump performance
When calculating the flow rate, it is necessary to know the pump performance during pumping. To do this, you can use the following methods:
- View flow meter or meter data;
- Read the passport for the pump and find out the performance by operating point;
- Calculate the approximate flow rate based on water pressure.
In the latter case, it is necessary to fix a pipe of smaller diameter in a horizontal position at the outlet of the water-lifting pipe. And make the following measurements:
- Pipe length (min. 1.5 m) and its diameter;
- Height from the ground to the center of the pipe;
- The length of the jet from the end of the pipe to the point of impact on the ground.
After receiving the data, you need to compare them using a diagram.
Compare the data by analogy with the example Measuring the dynamic level and flow rate of a well must be done with a pump with a capacity no less your estimated peak water flow.
Simplified calculation
Well flow rate is the ratio of the product of water pumping intensity and the height of the water column to the difference between dynamic and static water levels. To determine the flow rate of a well, the following formula is used:
Dt = (V/(Hdin-Nst))*Hv, Where
- Dt – required flow rate;
- V – volume of pumped liquid;
- Hdin – dynamic level;
- Hst – static level;
- Hv – height of the water column.
For example, we have a well 60 meters deep; the statics of which is 40 meters; the dynamic level when operating a pump with a capacity of 3 cubic meters per hour was established at around 47 meters.
In total, the flow rate will be: Dt = (3/(47-40))*20= 8.57 cubic meters/hour.
A simplified measurement method involves measuring the dynamic level when the pump is operating at one capacity; for the private sector this may be sufficient, but not to determine the exact picture.
Specific flow rate
With an increase in pump performance, the dynamic level, and therefore the actual flow rate, decreases. Therefore, water intake is more accurately characterized by the productivity coefficient and specific flow rate.
To calculate the latter, you should make not one, but two measurements of the dynamic level at different indicators water intake intensity.
The specific flow rate of a well is the volume of water released when its level decreases for each meter.
The formula defines it as the ratio of the difference between the larger and smaller values of water intake intensity to the difference between the values of the drop in the water column.
Dsp=(V2-V1)/(h2-h1), Where
- Dsp – specific flow rate
- V2 – volume of pumped water during the second water intake
- V1 – primary pumped volume
- h2 – decrease in water level at the second water intake
- h1 – level reduction at the first water intake
Returning to our conditional well: with water intake at an intensity of 3 cubic meters per hour, the difference between dynamics and statics was 7 m; when re-measuring with a pump capacity of 6 cubic meters per hour, the difference was 15 m.
In total, the specific flow rate will be: Dsp = (6-3)/(15-7)= 0.375 cubic meters/hour
Real flow rate
The calculation is based on the specific indicator and the distance from the ground surface to the top point of the filter zone, taking into account the condition that pump unit will not be shipped below. This calculation is as close to reality as possible.
DT= (Hf-Hst) * Doud, Where
- Dt – well flow rate;
- Hf – distance to the beginning of the filtration zone (in our case we will take it as 57 m);
- Hst – static level;
- Dsp – specific flow rate.
In total, the real flow rate will be: Dt = (57-40)*0.375= 6.375 cubic meters/hour.
As you can see, in the case of our imaginary well, the difference between the simplified and subsequent measurements was almost 2.2 cubic meters per hour in the direction of decreasing productivity.
Decrease in flow rate
During operation, the well's productivity may decrease; the main reason for the decrease in flow rate is clogging, and to increase it to the previous level, it is necessary to clean the filters.
Over time, the impellers of a centrifugal pump can wear out, especially if your well is in sand, in which case its performance will decrease.
However, cleaning may not help if you initially have a low-yield water well. The reasons for this are different: the diameter of the production pipe is insufficient, it fell past the aquifer, or it contains little moisture.
Calculation of fitting diameter
The diameter of the wellhead fitting for gas wells is determined by the formula:
Where is the diameter of the fitting, mm;
Flow coefficient;
Qg - gas flow rate, m3/day;
Рbur - buffer pressure, according to field data atm.
Let's calculate the diameter of the wellhead choke hole using formula (2.16) for well No. 1104:
Calculation of the minimum well flow rate ensuring the removal of the liquid phase
When operating gas wells, the most common complication is the influx of liquid phase (water or condensate). In this case, it is necessary to determine the minimum bottomhole flow rate gas well, in which there is no accumulation of liquid at the bottom with the formation of a liquid plug.
The minimum flow rate of a gas well (in m3/day), at which a liquid plug does not form at the bottom, is calculated by the formula:
Where is the minimum gas velocity at which a liquid plug does not form, m/s;
Temperature under standard conditions, K,
Reservoir temperature, K,
Bottomhole pressure, MPa,
Atmospheric pressure, MPa,
Internal diameter of the tubing, according to the project = 0.062 m,
Gas supercompressibility coefficient.
Minimum gas velocity at which a water plug does not form:
Minimum gas velocity at which a condensate plug does not form:
When operating gas wells, the most common complication is the influx of liquid phase (water or condensate). In this case, it is necessary to determine the minimum bottomhole flow rate of a gas well, at which liquid accumulation at the bottom with the formation of a liquid plug does not yet occur.
Using formulas (2.17-2.19), we calculate the minimum flow rates of gas condensate well No. 1104 of the Samburg oil and gas condensate field, at which condensate will not settle at the bottom:
Minimum flow rate at which water is removed:
Or thousand m3/day.
Minimum gas velocity at which all condensate is carried to the surface:
Minimum flow rate for condensate removal:
Or thousand m3/day.
Comparing the results obtained, it can be noted that, under other constant conditions, complete removal of condensate is possible at higher flow rates of a gas well than complete removal of water.
Calculation of technological efficiency of sidewalls
The amount of additionally produced gas during the calculation period due to the drilling of a horizontal lateral trunk of well No. 1104 in the productive formation is determined by the formula:
Where is the amount of oil actually produced by the well during the billing period;
The value of theoretical (estimated) oil production from a well during the calculation period in the absence of a horizontal wellbore in the productive formation, .
Where is the flow rate of a well with a horizontal well and a vertical one;
Vertical well flow rate, .
Correction factor taking into account compliance with additional gas production and production of recoverable reserves, units. For the first 2 years in = 1;
The amount of additionally produced gas condensate is determined by the formula:
Where is the amount of additionally produced gas condensate during the billing period due to the drilling of a horizontal lateral trunk, t;
Condensate-gas factor, according to field data kg/m3.
Calculation for 2 years using formulas (2.23-2.34):
In this section, a calculation was made of technological efficiency by drilling a horizontal trunk in a vertical well. Comparison of “actual” indicators of site development with horizontal wells with indicators basic version, once again shows the undeniable advantage of using BGS in the development of low-productive formations of relatively small effective thickness. During the period of operation in natural mode for two years when using horizontal wells, additional production will be natural gas and tons of gas condensate, which is 9 times higher than the base version.
Conclusions on the second section
1. Analysis modern methods intensification of natural gas and gas condensate production showed the promise of using methods such as hydraulic fracturing and sidetracking in vertical and directional wells at the Samburgskoye oil and gas condensate field. Among these methods of production intensification, sidetracking is one of the most effective in the conditions of the Samburgskoye field.
2. The use of sidetracking technology in vertical and directional wells of the Samburg oil and gas condensate field to convert wells to horizontal ones will not only reduce drilling volumes, increase the flow rate and profitability of wells, but also more rationally use reservoir energy, due to lower depressions on the reservoir.
3. Based on an analysis of the stock of producing wells and the density of residual mobile reservoir gas reserves, candidate well No. 1104 was selected for sidetracking. For a larger scale implementation of this technology, it is recommended to conduct additional research in order to identify other wells that are promising for sidetracking.
3. Technological calculation of the parameters of a candidate well using the method of Aliev Z.S. showed that the design well flow rate after sidetracking can increase more than 10 times from 89.3 thousand m3/day to 903.2 thousand m3/day.
4. Calculations of the profile of well No. 1104 were performed. At the same time, “cutting a window” in the EC at a depth of 2650 m was chosen as the drilling method technology, with a maximum curvature angle of 2.0° per 10 m in the interval 2940 - 3103 m vertically and a horizontal section length of 400 m.
5. Calculation of the main parameters of the technological operating mode of the well made it possible to determine the diameter of the wellhead choke, the minimum gas velocities (m/s, m/s) at the bottom, ensuring the complete removal of water and gas condensate to the surface, as well as the minimum flow rates at which no gas is formed. bottomhole liquid plugs (thousand m3/day, thousand m3/day). Under other constant conditions, complete removal of condensate is possible at higher flow rates of a gas well than complete removal of water.
6. Calculation of the technological efficiency of sidetracking shows the undeniable advantage of using this technology in the development of low-productive formations of relatively small effective thickness. During the period of operation in natural mode for two years, additional production will amount to natural gas and tons of gas condensate, which is 9 times higher than these figures above the base option.
7. Thus, the calculations performed for the use of sidetracking at the Samburgskoye oil and gas condensate field have shown their effectiveness, and this technology can be recommended as a method for intensifying the production of natural gas and gas condensate at this field.
Well flow rate is main well parameter, showing how much water can be obtained from it in a certain period of time. This value is measured in m 3 /day, m 3 /hour, m 3 /min. Consequently, the greater the well's flow rate, the higher its productivity.
You need to determine the flow rate of a well first of all in order to know how much liquid you can count on. For example, is there enough water for uninterrupted use in the bathroom, in the garden for watering, etc. In addition, this parameter is a great help in choosing a pump for water supply. So, the larger it is, the more efficient the pump can be used. If you buy a pump without paying attention to the flow rate of the well, it may happen that it will suck water out of the well faster than it will be filled.
Static and dynamic water levels
In order to calculate the flow rate of a well, it is necessary to know the static and dynamic water levels. The first value indicates the water level in a calm state, i.e. at a time when water was not pumped out yet. The second value determines the steady water level while the pump is running, i.e. when the speed of its pumping is equal to the speed of filling the well (water stops decreasing). In other words, this flow rate directly depends on the performance of the pump, which is indicated in its passport.
Both of these indicators are measured from the surface of the water to the surface of the earth. The unit of measurement most often chosen is the meter. So, for example, the water level was fixed at 2 m, and after turning on the pump it settled at 3 m, therefore, the static water level is 2 m, and the dynamic one is 3 m.
I would also like to note here that if the difference between these two values is not significant (for example, 0.5-1 m), then we can say that the well’s flow rate is large and most likely higher than the pump’s performance.
Calculation of well flow
How is a well's flow rate determined? This requires a high-performance pump and a measuring container for pumped-out water, preferably as much as possible large sizes. It is better to consider the calculation itself using a specific example.
Input 1:
- Well depth - 10 m.
- Beginning of the level of the filtration zone (zone of water intake from the aquifer) - 8 m.
- Static water level - 6 m.
- The height of the water column in the pipe is 10-6 = 4m.
- Dynamic water level - 8.5 m. This value reflects the remaining amount of water in the well after pumping 3 m 3 of water from it, with the time spent on this being 1 hour. In other words, 8.5 m is the dynamic water level with a debit of 3 m 3 / hour, which decreased by 2.5 m.
Calculation 1:
Well flow rate is calculated using the formula:
D sk = (U/(H din -N st)) H in = (3/(8.5-6))*4 = 4.8 m 3 /h,
Conclusion: well flow rate is 4.8 m 3 /h.
The presented calculation is very often used by drillers. But it carries a very large error. Since this calculation assumes that the dynamic water level will increase in direct proportion to the rate of water pumping. For example, when pumping water increases to 4 m 3 /h, according to him, the water level in the pipe drops by 5 m, but this is incorrect. Therefore, there is a more accurate method that includes the parameters of the second water intake in the calculation to determine the specific flow rate.
What should you do? After the first water intake and data reading (previous option), it is necessary to allow the water to settle and return to its static level. After this, pump out water at a different speed, for example, 4 m 3 / hour.
Input 2:
- The well parameters are the same.
- Dynamic water level - 9.5 m. At a water intake intensity of 4 m 3 /h.
Calculation 2:
The specific flow rate of a well is calculated using the formula:
D y = (U 2 -U 1)/(h 2 -h 1) = (4-3)/(3.5-2.5) = 1 m 3 / h,
As a result, it turns out that an increase in the dynamic water level by 1 m contributes to an increase in flow rate by 1 m 3 / h. But this is only provided that the pump is located no lower than the beginning of the filtration zone.
The real flow rate here is calculated by the formula:
D sk = (N f -N st) D y = (8-6) 1 = 2 m 3 / h,
- Hf = 8 m- the beginning of the level of the filtration zone.
Conclusion: well flow rate is 2 m 3 /h.
After comparison, it is clear that the well flow rates, depending on the calculation method, differ from each other by more than 2 times. But the second calculation is also not accurate. The well flow rate, calculated through the specific flow rate, is only close to the real value.
Ways to increase well production
In conclusion, I would like to mention how you can increase the flow rate of a well. There are essentially two ways. The first way is to clean the production pipe and filter in the well. The second is to check the functionality of the pump. Suddenly, precisely because of this, the amount of water produced decreased.
CALCULATION OF THE PRODUCTION OF GAS WELLS WITH A HORIZONTAL END Ushakova A.V.
Ushakova Anastasia Vadimovna - master's student, department of development and operation of oil and gas fields, Tyumen Industrial University, Tyumen
Abstract: to justify the operating mode of a well and predict development parameters, it is necessary, first of all, to calculate the productivity of the well - to establish the relationship between the well flow rate and depression. The well flow rate, as well as the depth of the formation into which drilling is planned, affect the well design; in addition, when choosing a design, it is necessary to ensure a minimum value of pressure loss along the wellbore. In the case of a horizontal (flat) well, pressure losses also appear in the horizontal part of the wellbore. This paper describes the main types of hydraulic resistance encountered when gas moves to a horizontal well, and provides methods for calculating the inflow profile and flow rate of a horizontal well.
Keywords: horizontal gas well, inflow profile, pressure loss.
The issue of gas inflow to horizontal wells was dealt with by Z.S. Aliev, V.V. Sheremet, V.A. Chernykh, Sokhoshko S.K. , Telkov A.P. .
The main difficulties in analytical solutions to problems of inflow to horizontal wells are associated with the nonlinear relationship between the pressure gradient and filtration rate, as well as the determination of friction losses during the movement of gas and gas-condensate mixture in a horizontal well, especially with significant flow rates and long well lengths.
Sokhoshko S.K. identifies 3 groups of works devoted to the productivity of horizontal gas wells:
1 Relatively accurate decision on gas inflow to a horizontal well at linear dependence between pressure gradient and filtration rate;
2. An approximate solution to the problem of gas inflow to a horizontal well with a nonlinear relationship between the pressure gradient and filtration rate;
3 Exact numerical solution to the problem of gas inflow to a horizontal well under a nonlinear filtration law, set out in the work and the linear law;
The disadvantage of these works is that they assume a constant bottomhole pressure along the length of a horizontal wellbore, and also do not take into account the influence of wellhead pressure on the productivity of horizontal wells. As a result, a direct relationship between productivity and the length of the horizontal section was obtained.
However, many researchers claim that this performance calculation scheme is fundamentally incorrect. For horizontal wells, knowledge about the distribution of bottomhole pressure along the wellbore has more important role than for vertical ones. This is due to the fact that the area of the drainage zone in a horizontal well is larger compared to a vertical one.
One of the solutions, which takes into account the change in bottomhole pressure when calculating productivity, was obtained by Z.S. Aliyev and A.D. Sedykh. Also, the solution of the inflow profile for the first time takes into account all types of hydraulic resistance, including local resistance perforations, their location and density, as well as taking into account the angle of inclination for a horizontal gas well, was obtained by Sokhoshko S.K. .
| 37 | Modern innovations No. 2(30) 2018
References
1. Aliev Z.S., Sheremet V.V. Determination of the productivity of horizontal wells that penetrated gas and gas-oil formations M.: Nedra, 1995.
MINISTRY OF EDUCATION AND SCIENCE OF THE RUSSIAN FEDERATION
higher vocational education
"Tyumen State Oil and Gas University"
Features of oil field development with horizontal wells
Guidelines
For independent work in the discipline “Features of field development with horizontal wells” for masters studying in the specialty 131000.68 “Oil and Gas Engineering”
Compiled by: S.I. Grachev, A.S. Samoilov, I.B. Kushnarev
Ministry of Education and Science of the Russian Federation
Federal state budget educational institution
higher professional education
"Tyumen State Oil and Gas University"
Institute of Geology and Oil and Gas Production
Department of Development and Operation of Oil and Gas Fields
Guidelines
In the discipline “Features of oil field development with horizontal wells”
for practical, laboratory classes and independent work for bachelors of direction 131000.62 “Oil and Gas Engineering” for all forms of education
Tyumen 2013
Approved by the editorial and publishing council
Tyumen State Oil and Gas University
The guidelines are intended for bachelors of the direction 131000.62 “Oil and Gas Engineering” for all forms of study. The guidelines provide the main tasks with examples of solutions in the discipline “Features of developing oil fields with horizontal wells.”
Compiled by: Associate Professor, Ph.D. Samoilov A.S.
Associate Professor, Ph.D. Fominykh O.V.
laboratory assistant Nevkin A.A.
© state educational institution of higher professional education
"Tyumen State Oil and Gas University" 2013
INTRODUCTION 2
Topic 1. Calculation of production rates of wells with horizontal termination and comparison of results. 7
Topic 2. Calculation of the flow rate of a horizontal well and an inclined well with a hydraulic fracturing fracture using the given formulas, comparing the results. 2
Topic 3. Calculation of the flow rate of a multilateral well. 17
Topic 4. Calculation of the optimal grid of horizontal wells and the comparative efficiency of their work with vertical ones. 21
Topic 5. Interpretation of the results of hydrodynamic studies of wells with horizontal completion in steady-state modes (according to the method of V.S. Evchenko). 2
Topic 6. Production rate of a horizontal well with hydraulic fractures located in an anisotropic, band-like formation. 34
Topic 7. Calculation of the maximum anhydrous drawdown of a well with a horizontal end…………………………………………………………………………………30
Topic 8. Modeling of unsteady fluid movement to a horizontal well using a two-zone scheme……………………………45
INTRODUCTION
With large-scale implementation in the early 2000s and over the next decade into the field development system Western Siberia horizontal wells (HS) and horizontal lateral trunks (HSS), accelerated production of oil reserves was achieved with a quick return on investment without the construction of new wells. The implementation was carried out in a prompt manner, not always consistent with the adopted design solutions, or by transformation existing system development. However, without a systematic justification for the technology of horizontal opening and operation of objects, the design values of the oil recovery factor (ORF) are not achieved.
IN recent years horizontal opening technology is given much more attention when designing a development system; in some companies, the justification for the construction of each horizontal well is carried out in the form of a mini-project. This was also influenced by the global financial crisis, when, in order to optimize production, the error and the share of uncertainty were reduced to a minimum. New approaches have been applied to horizontal drilling technology, as evidenced by the operating results of GS and BGS built since 2009 (more than 350 wells have been built at Surgutneftegaz OJSC, more than 200 wells at Lukoil OJSC, and more than 100 wells at TNK-BP. , in OJSC NGK Slavneft there are more than 100 wells, in OJSC Gazprom Neft there are more than 70 wells, in OJSC NK Rosneft there are more than 50 wells, in OJSC NK RussNeft there are more than 20 wells).
It is known that it is not enough to determine only the basic parameters of the use of horizontal wells: length, profile, location of the trunk relative to the roof and base, limiting technological operating conditions. It is necessary to take into account the placement and parameters of the well pattern, formation patterns and regulation of their operating modes. It is necessary to create fundamentally new methods for monitoring and managing the production of oil reserves, especially for complex deposits, which will be based on a reliable study geological structure through the study of horizontal wells, the dependence of oil flow rate on the heterogeneity of the geological structure and hydraulic resistance along the length, creating uniformity in the production of oil reserves throughout the entire volume of the reservoir of the drained horizontal well, high-precision determination of the drainage zone, the possibility of carrying out and predicting the effectiveness of methods for increasing oil recovery, determining the main rock stresses, the efficiency of the flooding system directly depends on their consideration and mechanical methods impact on the formation (hydraulic fracturing).
The purpose of this guideline is to provide students with the knowledge used by modern science and production in well productivity management.
The methodological instructions for each task by topic present a calculation algorithm and give an example of solving a typical problem, which significantly helps the successful completion of the task. However, its application is possible only after studying the theoretical foundations.
All calculations should be carried out within the framework of the International System of Units (SI).
Theoretical foundations The disciplines are well presented in textbooks, the links of which are given.
Topic 1. Calculation of production rates of wells with horizontal termination and comparison of results
To determine the oil production rate in a single horizontal well in a uniformly anisotropic formation, the S.D formula is used. Joshi:
Where, Q g– oil flow rate of a horizontal well m 3 /sec; k h– horizontal permeability of the formation m2; h– oil-saturated thickness, m; ∆P– reservoir drawdown, Pa; μ n– oil viscosity Pa s; B 0– volumetric coefficient of oil; L– length of the horizontal section of the well, m; r c– wellbore radius in the productive formation, m; – semimajor axis of the drainage ellipse (Fig. 1.1), m:
, (1.2)
Where Rk– radius of the power circuit, m; – permeability anisotropy parameter, determined by the formula:
kv– vertical permeability of the formation, m2. The calculations assumed a vertical permeability of 0.3· k h, the averaged parameter of terrigenous sediments of Western Siberia, also for a reliable calculation the condition - , must be met.
Figure 1.1 - Inflow diagram to a horizontal wellbore in a circular formation
Borisov Yu.L. when describing an elliptic flow, he proposed another condition for determining Rk. The main radius of the ellipse (Fig. 1.2), which is the average value between the semi-axes, is used as this value:
(1.4)
Figure 1.2 - Scheme of inflow to a horizontal wellbore in a circular formation
General formula for inflow to the gas station, obtained by Borisov Yu.P., has next view:
, (1.5)
Where J– filtration resistance, determined by the formula:
. (1.6)
Giger proposes to use formula (1.8), where the filtration resistance J take expression
(1.7)
The general formula for the inflow to the gas station, obtained Giger is similar to the equations of previous authors:
.
(1.8)
All symbols parameters are similar to those presented for the Joshi S.D. equation.
Task 1.1. For the geological and physical conditions of the PK 20 formation of the Yarainerskoye field, presented in Table 1.1, calculate the flow rate of a well with a horizontal end Q g using the presented methods, compare the results obtained, determine the optimal length of the horizontal section according to the graph of the dependence of the well flow rate on the length of the horizontal line for 10 values (from the initial one) with a step of 50 meters for the solutions of the considered authors.
Table 1.1
Solution. The problem is solved in the following order:
1. Let’s calculate the flow rate of the gas pipeline using the Joshi S.D. method. To do this, it is necessary to determine the anisotropy parameter from expression 1.3 and the semimajor axis of the drainage ellipse (expression 1.2):
Substituting the results obtained into expression 1.1 we obtain,
2. Let's calculate the flow rates of the gas pipeline using the method of Borisov Yu.P.
Filtration resistance determined by formula 1.6:
To determine the daily flow rate, we multiply the result by the number of seconds in a day (86,400).
3. Let's calculate the flow rates of the gas pipeline using the Giger method.
Filtration resistance J take expression (1.7)
We determine the flow rate of the gas pipeline:
To determine the daily flow rate, we multiply the result by the number of seconds in a day (86,400).
4. Compare the results obtained:
5. Let us calculate the well flow rates for 20 values of the length of the horizontal section in increments of 50 meters using the presented methods and construct a graphical dependence:
| L length of horizontal section | HS flow rate, m 3 /day (Joshi S.D.) | HS flow rate, m 3 /day (Borisova Yu.P.) | HS flow rate, m 3 /day (Giger) |
| 1360,612 | 1647,162 | 1011,10254 | |
| 1982,238 | 2287,564 | 1318,32873 | |
| 2338,347 | 2628,166 | 1466,90284 | |
| 2569,118 | 2839,562 | 1554,49788 | |
| 2730,82 | 2983,551 | 1612,26295 | |
| 2850,426 | 3087,939 | 1653,21864 | |
| 2942,48 | 3167,09 | 1683,77018 | |
| 3015,519 | 3229,168 | 1707,43528 | |
| 3074,884 | 3279,159 | 1726,30646 | |
| 3124,085 | 3320,28 | 1741,70642 | |
| 3165,528 | 3354,7 | 1754,51226 | |
| 3200,912 | 3383,933 | 1765,32852 | |
| 3231,477 | 3409,07 | 1774,58546 | |
| 3258,144 | 3430,915 | 1782,59759 | |
| 3281,613 | 3450,074 | 1789,60019 | |
| 3302,428 | 3467,016 | 1795,77275 | |
| 3321,015 | 3482,103 | 1801,2546 | |
| 3337,713 | 3495,624 | 1806,15552 | |
| 3352,797 | 3507,811 | 1810,56322 | |
| 3366,489 | 3518,853 | 1814,54859 |
Figure 1.3 – Dependence of changes in well flow rate on the length of the horizontal section
Conclusions: Based on the results of calculating the predicted flow rate of a horizontal well using the methods of Joshi S.D., Borisov Yu.P., Giger for the geological and physical conditions of the PK 20 formation of the Yarainerskoye field, the following follows:
- with a slight difference (in the shape of the inflow in the horizontal projection) of the analytical models of the operation of horizontal wells that penetrated a homogeneously anisotropic formation in the middle between the roof and the bottom, the difference in the calculated flow rates is quite large;
- for the conditions of the PK 20 formation of the Yarainerskoye field, graphical dependences of the predicted well flow rate on the length of the horizontal section were constructed; according to the results of the analysis, it follows that the optimal options will be in the interval L 1=150 m. Q 1=2620 m 3 /day up to L 2=400 m. Q 2=3230 m 3 /day;
- the obtained values are the first approximate results of selecting the optimal length of the horizontal section of the well; further justification is based on clarifying the predicted flow rates using digital reservoir models and recalculating the economy, based on the calculation results of which the most rational option will be selected.
Options Task No. 1
| Var. | No. | Field, layer | HS length, m | h nn, m | Kh, mD | Kv, mD | Viscosity, mPa*s | Rpl, MPa | Rzab, MPa | Well radius, m | Rk,m |
| 210G | Yaraynerskoye, PK20 | 1,12 | 17,5 | 14,0 | 0,1 | ||||||
| 333G | Yaraynerskoye, AB3 | 1,16 | 6,0 | 0,1 | |||||||
| 777G | Yaraynerskoye, AV7 | 1,16 | 11,0 | 0,1 | |||||||
| 302G | Yaraynerskoye, AB10 | 1,16 | 21,8 | 13,0 | 0,1 | ||||||
| 2046G | Yaraynerskoe, BV2 | 0,98 | 21,1 | 13,7 | 0,1 | ||||||
| 4132G | Yaraynerskoe, BV4 | 0,98 | 23,1 | 16,0 | 0,1 | ||||||
| 4100G | Yaraynerskoe, BV4-1 | 0,98 | 23,3 | 16,0 | 0,1 | ||||||
| 611G | Yaraynerskoe, BV6 | 0,51 | 16,0 | 0,1 | |||||||
| 8068G | Yaraynerskoye, BV8 | 0,41 | 24,3 | 5,8 | 0,1 | ||||||
| Yaraynerskoye, BV8 | 0,41 | 24,3 | 11,2 | 0,1 | |||||||
| 215G | Yaraynerskoye, PK20 | 1,12 | 17,5 | 15,0 | 0,1 | ||||||
| 334G | Yaraynerskoye, AB3 | 1,16 | 11,0 | 0,1 | |||||||
| 615G | Yaraynerskoye, AV7 | 1,16 | 16,0 | 0,1 | |||||||
| 212G | Yaraynerskoye, AB10 | 1,16 | 21,8 | 15,0 | 0,1 | ||||||
| 2146G | Yaraynerskoe, BV2 | 0,98 | 21,1 | 17,8 | 0,1 | ||||||
| 4025G | Yaraynerskoe, BV4 | 0,98 | 23,1 | 13,0 | 0,1 | ||||||
| 513G | Yaraynerskoe, BV4-1 | 0,98 | 23,3 | 18,0 | 0,1 | ||||||
| 670G | Yaraynerskoe, BV6 | 0,51 | 19,5 | 0,1 | |||||||
| 554G | Yaraynerskoye, BV8 | 0,41 | 24,3 | 11,34 | 0,1 | ||||||
| 877G | Yaraynerskoye, BV8 | 0,41 | 24,3 | 16,2 | 0,1 | ||||||
| Continuation of Table 1.1 | |||||||||||
| 322G | Yaraynerskoye, PK20 | 1,12 | 17,5 | 14,9 | 0,1 | ||||||
| 554G | Yaraynerskoye, AB3 | 1,16 | 15,3 | 0,1 | |||||||
| 789G | Yaraynerskoye, AV7 | 1,16 | 12,7 | 0,1 | |||||||
| Yaraynerskoye, AB10 | 1,16 | 21,8 | 9,8 | 0,1 | |||||||
| 2475G | Yaraynerskoe, BV2 | 0,98 | 21,1 | 12,9 | 0,1 | ||||||
| 4158G | Yaraynerskoe, BV4 | 0,98 | 23,1 | 13,8 | 0,1 | ||||||
| Yaraynerskoe, BV4-1 | 0,98 | 23,3 | 18,2 | 0,1 | |||||||
| 688G | Yaraynerskoe, BV6 | 0,51 | 14,3 | 0,1 | |||||||
| 8174G | Yaraynerskoye, BV8 | 0,41 | 24,3 | 18,6 | 0,1 | ||||||
| 882G | Yaraynerskoye, BV8 | 0,41 | 24,3 | 15,2 | 0,1 |
Test questions.
