SU1328502A1 - Method of detecting intervals of beyond-casing fluid movement in well - Google Patents

Abstract

FIELD OF THE INVENTION The present invention relates to the oil industry. The purpose of the invention is to increase the reliability of the method by taking into account the effect of substitution convection. Before starting the well, background measurements of the fluid and fluid density are performed. After the wells are commissioned, when the fluid density in the bottom of the working formation is equal to or greater than the density of the fluid coming from the perforation interval, several thermograms and a series of density diagrams are recorded simultaneously in the interval under study. The intervals of behind-the-ring fluid motion are judged by the change in density and the presence of abrupt changes in the temperature gradient at each point of the studied interval. 3 il. § (L

Description

The invention relates to the oil industry and can be used to determine the annular fluid flow in oil and gas wells and injection wells.

The aim of the invention is to increase the reliability of detecting the annular motion intervals by taking into account the effects of convection substitutions, IQ

Figure 1-3 presents the results of studies in the implementation of the method on wells.

FIG. 1 - 3 are marked curves of 1 self-polarization of rocks (PS), curves 2 15 of the natural activity of rocks (HA), distribution of 3 densities (HGP) in an idle well, distribution of 4 density of damages in the course of well operation (according to HGP), thermogram- 20 we are 5-10.

The method is carried out as follows.

The thermometer-density meter is lowered into the well, the background distribution of the temperature and density of the fluid in the test interval is recorded, and a series of measurements is carried out immediately after the start of the well. If the fluid density in the aeral zone of the working formation is not less than the fluid density / coming from the perforation interval, the annular circulation is determined by changing the fluid density and the presence of abrupt changes in the temperature gradient at each point of the studied interval. If the density of the fluid in the bottom of the working formation is lower than the density of the fluid coming 40 from the perforation interval, then the density of the fluid in the sump of the well is increased by any known means, for example, by increasing the salinity, after which measurements are made. g

Example 1. Record the background thermogram 5 before the start of operation of the compressor and pnogram 3 (figure 1). After that, gQ inflows are excited from the well by means of a compressor and temperature, temperature and density distributions are measured: thermogram 6 — 1 hour after the compressor starts operation; thermogram 7 - after 2 hours after the start of operation of the compressor; thermogram 8 - 2 hours after the compressor stops; thermogram 9 - 3 hours after the compressor stops; ter35

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Q

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5 o 0 g

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Program 10 - 4 hours after the compressor stops. Simultaneously with the measurement 10, the ixTOTHocTH distribution in the wellbore (curve 4) is measured.

From the results of the research, it can be seen that in the depth interval of 1334.8-1349 m, a distortion of the natural thermal floor is observed, associated with convective heat transfer. In the same interval, on the measurements of the densitometer in the process of operation (curve 4), a decrease in the density of the liquid with depth is observed. Similar changes in density on measurements in the idle well are absent. This density distribution is associated with convection of the replacement of well fluid with highly mineralized, more dense fluid coming from the perforation interval.

Thus, the increased temp measurement temperature in the well sump in this case is associated with the convection of the substitution (the more dense formation fluid flows into the sump well). Zakolonna g. Dirkul qi is absent. This is also indicated by monotonic changes in the temperature and density of the fluid in the sump of the well.

PRI mme R 2. Record the background thermogram (curve 5) and the density distribution (curve 3) before the compressor starts (Fig. 2). After this, the wells excite the inflow with a compressor and measure the temperature and density; thermographer 6 — after JH after the start of drainage; thermogram 7 — 2 hours after the start of drainage; thermogram 8 - 3 hours after the compressor starts operation; thermogram 9 - after stopping the compressor after 4 hours of operation; density diagram 4 and thermogram 10 - 1 hour after the compressor stops. The increased rate of temperature change in the sump of the well, the fracture of the thermogram 7 at a depth of 1379 m, and the change in density allow us to conclude that convective transfer is due to ring-shaped movement of the LIQUID and convection of the substitution shown in measurements 8.9 and 10.

Thus, the irrigation of the well in this case occurs due to the annular movement of fluid from the underlying aquifers.

PRI me R 3. Record the background thermogram before the compressor starts (not shown in the graphs). After that, a stream is excited from the well by means of a compressor and measurements of the distribution of temperature, density and the position of the current bottom are taken: thermogram 5 - 1 hour after the compressor starts operation; thermogram 6 - after 2 h; thermogram 7 - 1 hour after the compressor stops; thermogram 8 - after 2 h; thermogram 9 - after 3 h; thermogram 10 — after 4 hours. Curve 11 — coupling locator before starting work, curve 12 — after compressor operation, curve 13 — after 3 days (Fig. 3).

A change in the natural thermal field and cementing anomalies with amplitudes of the order of 0.5 K are observed in the sump of the well. These changes are due to convection of substitution of solid rock particles leached from the formation and deposited in the sump of the well. On this, a change in the position of the current slab from 1564 to 1540 m in 6 hours of research is considered.

Claims (1)

Thus, the dynamic processes in the well sump in this case are associated with the convection of the substitution. (-Formula of the invention. Method of detecting intervals of the fluid phase flow in a well, including recording several thermograms in the studied interval Q after the well has been put into operation with their subsequent comparison, characterized in that, in order to increase the reliability of the method by taking into account the effect of convection at the same time, background measurements of the temperature and density of the fluid in front of the well are carried out; simultaneously with the thermograms, a series of density diagrams are recorded The Q start-up operation with fluid density in the bottom of the working formation equal to or greater than the fluid density is received from the perforation interval, and the back-up fluid movement intervals are judged by the change in density and the presence of abrupt changes in the temperature gradient at each point of the studied interval . P I eleven YY / 7 Well Well b 4sf R w .. C W m : H iSr nk 41 N: N % X 1 m R I V 12 Compiled by M. Tupysev Editor I. Nikolaichuk Tehred L. Serdyukova Proofreader V. But ha Order 3462 / 35Tgfazh 532Subscription VNIIP USSR State Committee for inventions and discoveries 113035, Moscow, Zh-355 Raushsk nab., D. 4/5 Production and Peschgraphic Enterprise, Uzhgorod, st. Project, 4