SU1446290A1 - Method of determining the locations of manifestations or caving-in in wells - Google Patents

Abstract

The invention relates to the study of oil and gas wells. The purpose of the invention is to determine the accuracy of determination. Liquid is supplied to the pipe string. The flow rate and the values of the fluid supplied and released from the annulus of the well are measured. Abrupt fluid changes. The rem is measured from the moment the fluid supply changes to its output with altered indicators. The depth of manifestations or debris is determined, over which the pressure loss in the annular space is established from the place of manifestation to the mouth. Establish the initial flow of the fluid. Re-change: stepwise flow after a time longer than the time taken to stabilize the production rate. A back pressure equal to the pressure loss is created at the wellhead. The depth of occurrence or debris is determined. Using this method allows you to obtain the necessary information without stopping the main process, 3 Il., 1 tab. yu (L

Description

4 4 ;:

oh

with

114A6290

refers to the research and other squash creation of cyri.

Eni - increase the point of location of the scatter in the wells,

a borehole with a zone defined by depth 10

ra not from pr about the two th

Bine X; Figures 2 and 3 show density change diagrams, respectively, when determining the approximate and refined depth of occurrence or debris in wells.

The peculiarity of the moving fluid as a communication channel is the delay of information for the time required to move the fluid, which has changed its properties from the location of a variety of properties (for example, a hole) to the place where the information sensors are installed on the surface. This time interval is defined by the expression

V q

Ls

(ABOUT

de V is the volume of the well annulus; drilling depth; fluid flow at the well outlet;

bore cavernosity ratio showing the ratio of the actual diameter or diameter of the well bore to the nominal S or D

L

Q. to

D, d

From here

S 0.785 (KD - d); - diameters; bits and pipes.

Qa „. S

(2)

The drilling fluid circulating fluid may be drilling mud, water, aerated tissue, in the operation of wells - oil, condensate; indicators of the solution, which are capable of being fixed by sensors and dismantled by recorders, are capacity, electrical resistance, gas content, precipitated rock particles.

When fluid flows through the annular space past the inflow zone.

0

five

0

five

0

five

0

located at any depth, it enters a foreign substance. A change in the fluid supply by the pumps leads to a change in the content of a foreign substance in the fluid volume. As a result, the fluid is divided into two parts with different contents and, consequently, indicators that sensors can detect which measure the values of B in the fluid, located above the area of interest, can be fixed. until the change in the flow rate, while the batteries are different from the indicators of the liquid that flowed past the gof zone after the change in flow.

When the flow rate changes over the communication channel, a signal is given in the form of a change in the liquid indices. In the practice of studying hydrothermal objects, mainly discontinuous and pulsed signals are used, rather than sinusoidal, trapezoidal, and t, n, t, e, varying smoothly, since experiments with such signals are associated with the use of special equipment and a large amount of time spent on the experiment; experiments with hopping signals do not require special equipment.

Therefore, in order to eliminate the error, the flow rate must be varied in steps, t, e. within one or several seconds, which, compared with the time of one cycle of circulation of the solution through the well, is abrupt or an instantaneous change in the flow rate.

The fixative on the mouth the time of the beginning of the change in consumption t, the time

 on the mouth

indicators other than

the time of leaving, the dynamics of changes in these properties until the stabilization tj, determine the time T taking into account the transport delay time 2,

Based on the expression (2), the distance from the wellhead to the inflow zone X is determined,

Changes in the solution parameters over time can be affected by changes in the flow resistance of the solution in the annular space due to changes in flow, since the pressure losses at the wellhead are proportional to the flow rates Sj.

WP + p,

kn;

R

R

kn

- pressure losses in pipes;

- ring pressure loss.

81,

P

space,

2 13

J

LQiJ. rCD + c

  L, (() (D + d)

(3)

where is x

hydraulic resistance coefficient;

p is the liquidity ratio in the annular space; L, is the length of pipes with different diameters.

A change in pressure loss from the site of production to the wellhead will entail a change in the flow rate of the flow (for example, during water supply) with some delay. A change in flow rate will lead to a change in the content of a foreign agent (vpd) in the solution flow after a change in the flow rate. Because of this, the fixed curve of the indicator of the solution - the time can be stepped at the site of a monotonous increase in the value of the indicator that does not allow to determine the inflection point, and therefore j will introduce an error in the definition.

Therefore, to improve the accuracy of determining the location of occurrences or debris S wells, according to the proposed method, after changing the flow rate, the depth of occurrence is approximately determined, and then the required back pressure to the fluid flow is calculated at the wellhead, equal to the hydraulic losses in the annulus Up to the mouth, and the measurement is repeated, but at the same time artificially creating a back pressure.

Due to the fact that a change in backpressure caused by a change in flow rate may entail a change in flow rate, re-measurement is performed after the formation-flow rate stabilizes.

The method is carried out as follows.

At the inlet 1 of the well, a liquid flows at the flow rate Q, and the exponent p. At the exit 2 of the well, the flowmeter 3 controls the flow and the device A is the value of the indicator p of the solution. After the development, the solution leaving the well changes its properties, t, e, the indicator becomes equal to p1, the flow rate Q; ,, Differential

A62904

flow q (Q ,, This means the beginning of the appearance.

The solution supply is changed by pumps from Q to Q, for example, by turning off one of the two operating pumps, and at the same time they begin to fix in time, the flow rate of outgoing solution Q is measured, which should be

10 QJ × After that, the time t of the beginning of the change in the indicator, t, - the stabilization of the indicator, is recorded. In the case of an increase in the production rate during this period of time, the calculation becomes 15 s impossible. Therefore, T t - t ,. The approximate depth of the manifestations is determined by the formula.

Then the -J solution is fed again with the QJ feed, the hydro loss is calculated

2Q in the annular space from the place of occurrence to the mouth,

Dp of a certain combination of pipe and bore diameters for the interval length of 1000 m and the calculated hydraulic hydrodynamics are presented in the table.

35

After some time T, the operation is repeated, but a back pressure is created at the wellhead equal to the hydraulic losses in the annular space from a depth of 40 x to the mouth. In this case, the hydrodynamic effect on the shtat is minimal or eliminated, therefore it is possible to determine Z from a curve in which there are no jumps 45 growth rate from p. I ° РЗ ° time t - to t. Based on this, T and the refined value of the depth X of the X

0

Example, Borehole (D

 215.9 mm, d 127 mm, K "1.07) when the bit was at a depth of 2000 m when r was washed with water, 1.0 g / cm i, the development of salt water began, as indicated by the differential flow q Qi - Q, 0 , A2 m / min, P2 capacity became equal to 1.03 g / cm. One pump was turned off and the output flow rate became Qi “2, A m / min, after

5 min - 2.6 m / min, i.e. production rate increased. The record of the plotter on the meter is shown in FIG. 2. After 13 minutes, the output level began to change and stabilized after 12 minutes at a value of p, 1.09 g / s. Approximately, the depth of progression is determined

2.4 13 07785 7ТТ07 072Т59 - 07Т27)

 1181.8 m.

The refinement of the pressure in the annular space due to the change in the flow rate is calculated. According to the table it is

, R oz | .P | .. | . „.,.,

Again restore the original flow by connecting the second pump, wait until Qj. Q i - 0.42 m / min, i.e. the bed rate is stabilized at the initial value and the operation is repeated; Record of the diagram on a ppotnomer is presented on fig.Z. The wire tangent at the inflection point is 0.6 min.

Calculating

y 2j, 4 (13

(1.07-0.0466 - 0.01bG) .0.785

 35

1236

m

In the case of applying the proposed method for determining the place of inflow of foreign matter in the production well, the flow rate can be made by replacing the nozzle at the wellhead :.

Accuracy of determining the location of zones

The inflow of foreign substances into the well can be increased by re-changing the flow rate, as well as by simultaneously measuring several physical properties of the solution (density, temperature, concentration, etc.).

0

five

0

five

0

35

0

five

Q

When using the proposed method in comparison with the known, it is possible to obtain the necessary information without stopping the main process, no complicated equipment is required for the measurements, since all the influences and measurements are carried out by technical means involved in the main process, pressure and temperature in the well do not impose restrictions for the application of this method, since all measurements are carried out at the mouth. In addition, the proposed method can be used in automated and automatic control systems for technological operations in drilling and oil production.

Claims (1)

Invention Formula A method for determining the location of occurrences or slips in wells, including supplying a fluid to a pipe string, measuring the flow rate and openers of the fluid supplied and emerging from the annulus of a well, determining the time of fluid movement with altered indicators along the annular space to the mouth and determining the depth of manifestations or scree, which differs in that, in order to improve the accuracy of the determination, the fluid supply is changed in steps, the time from the change in the supply of liquid to the output with changed indicators, determine the depth of occurrences or scree, which determine the pressure loss in the annular space from the occurrence or scree to the mouth, establish the initial flow of fluid, re-change it abruptly after a time that stabilizes the flow rate of the formation , a backpressure equal to the pressure loss is created at the wellhead, and the refined value of the depth of occurrence or debris is determined.  : R L fz t j - Hi 1 W7 105 - Ш Ш 0 z b 8 10 12 t 16 18 yy 2 t.Mun fig.d