The most mineral deposits in Russia have currently reached development stages III–IV while their extraction ratios run up barely 30–40% on average. New deposits discovered and exploited are incapable to add to hydrocarbon production required for the industrial development. In this respect, the advance in the oil industry increasingly more bank on the new methods of reservoir recovery enhancement, of which the most universal technique is stimulation by vibration. Vibrostimulation of oil reservoir can use both surface and downhole vibratory sources. One of the possible types of downhole vibratory sources can be designed using a power unit, hydraulic pump and an electromagnetic percussion unit (EPU) mutually connected and arranged on tubing in a well at the level of oil reservoir. This article discusses the structural layout of the vibratory source, the related test bench, the data of investigation of seismic signals obtained in testing a breadboard model of the downhole vibratory source, and the comparison of these test data with the seismic signals from the surface vibroplatform. The tests were carried out by the Institute of Mining, Siberian Branch RAS on the test grounds Zelenaya Gorka in Novosibirsk and in the town of Gorno-Altaisk on the bank of the Katun River. Seismic signals were recorded by sensors mounted on the tube simulating an oilwell casing and by sensors arranged in adjacent rock mass at a distance from a few meters to a few kilometers. Interpretation of these signals allows plotting the amplitude of the seismic signal of the pulse vibratory source versus the distance to the source. The generation efficiency of this vibratory source with capacity to 5 kW can be estimated from comparison with the emission of a monochrome surface vibratory source with the force Fm = 60 t and capacity 100 kW. Such sources are used by geophysical services as stationary seismic vibrators in dip shooting and were involved earlier by the Institute of Mining in studies of reservoir stimulation for enhancement of oil recovery. The comparison of these vibratory sources shows that at similar displacement amplitudes А » 1000 μm at the contact with the emitting surface (platform or tube), the pulse vibratory source signal attenuates worse with depth from the ground surface. The signal amplitude of this source is 10 times smaller at the same distance. On the other hand, regarding the signal amplitudes of the pulse downhole vibratory source ( А » 0.12×10–6 m) and the unbalance platform (кА*(0.005-0.01)×10–6 m) at a depth of 1.5–2 km, their ratio is А/А*» 24–12 in favor of the downhole vibrator. Comparing the sources in terms of specific indices (for example, specific amplitude—the ratio of emission amplitude to power intake А/P), it is seen that the pulse downhole vibratory source dominates the unbalance source by 10–25 times. Thus, the discussed downhole vibratory source steps largely back in favor of the vibrating platform when operated on the ground surface and is greatly ahead when generating the seismic field in a well at the level of oil-and-gas-reservoir.

For citation:  Simonov B. F., Oparin V. N., Kordubailo A. O., Vostrikov V. I. Field research of generation efficiency of downhole pulse vibratory source. MIAB. Mining Inf. Anal. Bull. 2019;(8):180-189. [In Russ]. DOI: 10.25018/0236-1493-2019-08-0-180-189.