SU825892A1 - Device for taking samples and hydrodynamic testing of formations - Google Patents

Description

The invention relates to geophysical exploration of wells, and in particular to devices for sampling and hydrodynamic studies of formations.

A device for sampling and production of hydrodynamic studies is known, including a housing, a sampler, a sealing element and a clamping system, which makes it possible to efficiently perform multiple measurements of formation characteristics fl] in one round-trip of the device into the well.

However, the known device 15 does not allow simultaneously taking measurements of hydrodynamic characteristics to take a sample of the formation fluid without impurities of clay cake and drilling mud, as well as to conduct a preliminary quality control of the sealing of the tested object.

A device is also known for sampling liquid, gas and producing hydrodynamic research * 5 formations, comprising a housing, a hydraulic actuator, a sampler, a clamping system, a sealing shoe, a sampler valve made in the form of a spring-loaded differential 30 piston with axial and radial channels, a large stage of which, on the one hand, is connected with a hydraulic actuator, on the other, with a borehole space, and small steps are connected respectively with the cavity of the sampler and with the borehole space [2].

The disadvantage of this device is the direct connection of the sampling point with the sampler, as a result of which the sample taken contains impurities of the drilling fluid and clay cake, and in the case of unreliable sealing, the sampler is filled with borehole fluid and the device must be removed to the surface in preparation for re-launching. The purpose of the invention is improving the quality of the samples taken.

This goal is achieved by the fact that the device is equipped with a sleeve rigidly mounted on the differential piston from the side of the small stage, communicating with the borehole space, and the sleeve forms an initial sampling chamber with the housing and the differential piston communicating with the sampler through the channels of the sleeve and the differential piston in the lowermost position last one.

Due to the formation of a preliminary chamber, the issue of preliminary quality control of sealing is also solved.

In FIG. 1 shows a device for sampling and hydrodynamic studies of formations in the initial position, FIG. 2 - the same, when working for hydrodynamic studies of formations, in FIG. 3 - the same for the reservoir tester.

The proposed device consists of a housing 1, inside of which there is a hydraulic actuator 2, a sampler 3, blocked by a layer in the form of a differential piston 4 with a sleeve 5. The piston 4 is spring-loaded with a spring 6 relative to the housing 1. A sealing shoe 7 is installed on the housing 1 and there is a pressure system 8.

In the housing 1, channels A are made, communicating the hydraulic actuator 2 with a cavity B located above the larger stage 9 of the differential piston 4, as well as channels C, which communicate the suction cavity G of the sealing shoe 7 with the initial sampling chamber D located above the small stage 10 of the differential piston 4. In the differential piston 4., an axial channel E and a radial channel I are made, which through channel K in the sleeve 5 and the radial channel L in the housing 1 communicate with channel B. A pressure sensor 11 is installed in channel B, cavity M is under a larger stage 12 differential piston 4 communicates with channel N with the borehole space. The housing 1 also has a position sensor 13.

The device operates as follows.

In the device mode for hydrodynamic: formation research (Fig. 2), after the device is lowered for a specified research interval, the hydraulic actuator 2 is turned on, and overpressure is created in channel A, using the clamping system 8 and the sealing shoe 7, the sampling section is sealed. The pressure in the channel A increases, the differential piston 4 with the sleeve 5 moves downward, compressing the spring 6, and the volume D, which forms the initial sampling chamber, is freed. Channel And at the same time disconnected from the borehole space.

Chamber D is filled with the first part of the sample containing impurities of clay cake material and drilling fluid, while one of the three possible pressure readings is taken with a pressure sensor 11 located in channel B: drilling fluid pressure (if the seal is broken), low pressure (if the seal the shoe is installed in an impermeable layer) or pressure reduction, followed by an increase in reservoir pressure (if the device is installed in the "Permeable zone).

_ After the sensor 11 fixes the pressure of one of the indicated positions, all actuators easily return to their original position by reducing the pressure in the hydraulic system. The selected fluid from 1 <amera D is discharged into the well and the device is ready for the next test.

When the device is operating as a reservoir tester, the first sample is taken into chamber D using the method described above. If the device is installed in the permeable zone and the pressure sensor has detected a decrease in pressure with 20 subsequent increase to reservoir pressure, the hydraulic actuator 2 is switched on again, while the differential piston 4 moves to the extreme. the lower position (Fig. 3), -, Channel 25 And communicates with the sampler, and sleeve 5, opening channel L, communicates channel B with the sampler 3. An uncontaminated reservoir fluid sample, bypassing tank D, fills 3Q sampler 3. The filling process is monitored and detected by the pressure sensor 11. After sampling, all actuators return to their original position, • as a differential piston 4 under the action of the spring 6, the rest under the influence of hydrostatic pressure 'and pressure reduction in the hydraulic actuator 2.

Thus, in one descent 40 ascent, it is possible to investigate all points of interest and formations on the inflow with measuring reservoir pressure in the interval of interest to take a sealed sample for removal to 45 surface.

The proposed device will make it possible to increase the efficiency of research by improving the quality of the sample taken and repeated sampling50 and will make it possible to preliminarily examine all the intervals of interest for inflow and pressure during one run into the well. Consequently, due to a significant reduction in tripping operations, a positive economic effect will be obtained.

Claims (2)

1. Authors certificate of the USSR 541029, cl. E 21 V 49/02, 1974. ABOUT 2. Authors certificate of the USSR 541977, cl. E 21 V 49/02, 1974 (prototype). / / / 7Z777 // j //// 77 /// / j // Y //// 7 / Z 9US.3