SU1002996A1

SU1002996A1 - Seismic prospecting method

Info

Publication number: SU1002996A1
Application number: SU813313468A
Authority: SU
Inventors: Валерий Аркадьевич Силаев
Original assignee: Камское Отделение Всесоюзного Научно-Исследовательского Геологоразведочного Нефтяного Института
Priority date: 1981-07-09
Filing date: 1981-07-09
Publication date: 1983-03-07

Description

Изобретение относится к сейсми- ¹ ческой разведке, использующей скважи-, ны, и может применяться при поисках и разведке месторождений нефти и газа и других полезных ископаемых.This invention relates to seismic exploration ¹ cal using skvazhi-, us, and can be used in prospecting for oil and gas, and other minerals.

Известен способ сейсмической разведки, основанный на последовательном возбуждении упругих колебаний на разных глубинах ниже резких границ и регистрации их приемниками, установленными на поверхности земли (1].A known method of seismic exploration, based on the sequential excitation of elastic vibrations at different depths below sharp boundaries and their registration by receivers mounted on the surface of the earth (1].

Недостатком данного способа является невозможность размещения зарядов взрывчатых веществ ВВ и проведение взрывов пр всему стволу скважины в интервалах разреза, сложенных сыпучими терригенными породами из-за опасности создания обвалов, закупорки и ликвидации скважины.The disadvantage of this method is the impossibility of placing explosive explosive charges and conducting explosions all over the wellbore in the intervals of the section, composed of loose terrigenous rocks due to the risk of collapses, blockage and liquidation of the well.

Наиболее близким к изобретению техническим решением является способ сейсмической разведки, основанный на возбуждении колебаний в скважине, 'заполненной жидкостью, зарядами взрывчатых веществ, и регистрации на земной поверхности дифрагированных волн, обусловленных искусственными неоднородностями, расположенными в скважине £2]. ’θClosest to the invention, the technical solution is a seismic exploration method based on the excitation of vibrations in a well filled with a fluid, explosive charges, and registration of diffracted waves on the earth's surface due to artificial heterogeneities located in a well of £ 2]. ’Θ

Недостатком известного способа является невозможность проведения взры.вов на участках незацементированной обсадной колонны труб, которое сопровождается деформацией колонны, закупоркой и ликвидацией скважины.The disadvantage of this method is the impossibility of carrying out explosions in areas of an uncemented casing pipe string, which is accompanied by column deformation, blockage and liquidation of the well.

Кроме того, глубина погружения заряда ВВ и величина изучаемого интервала покрывающей толщи ограничена длиной обсадной трубы.In addition, the depth of immersion of the explosive charge and the size of the studied interval of the overburden are limited by the length of the casing.

Целью изобретения является повышение детальности исследования строения интервалов пород, неблагоприятных для проведения возбуждения колебаний.The aim of the invention is to increase the detail of the study of the structure of intervals of rocks, unfavorable for the excitation of oscillations.

Поставленная цель достигается тем, что согласно способу сейсмической разведки, основанному на возбуждении колебаний в скважине, заполненной жидкостью, зарядами взрывчатого вещества, и регистрации на земной поверхности дифрагированных волн, обусловленных искусственнымш неоднородностями, расположенными в скважине, в качестве искусственной неоднородности, расположенной в скважине используют нижюою часть колонны бурильных труб, для каждого положения которой в интервале исследований проводят возбуждение колебаний на забое скважины.This goal is achieved by the fact that according to the method of seismic exploration, based on the excitation of oscillations in a well filled with liquid, explosive charges, and registration on the earth's surface of diffracted waves caused by artificial inhomogeneities located in the well, an artificial inhomogeneity located in the well is used the lower part of the drill pipe string, for each position of which in the research interval, oscillations are excited at the bottom of the well.

Сущность способа заключается в следующем.The essence of the method is as follows.

Колебания, возбужденные на забое скважины, достигая нижней части колонны бурильных труб, преобразуются в дифрагированные волны, которые регистрируются на земной поверхности. Перемещая колонну бурильных труб вдоль ствола поверхности, можно поместить источник дифрагированных волн в любой участок исследуемой среды и определять по дифрагировантной волне ее скоростную характеристику.Fluctuations excited at the bottom of the well, reaching the bottom of the drill pipe string, are converted into diffracted waves that are recorded on the earth's surface. Moving the drill pipe string along the surface bore, it is possible to place the source of diffracted waves in any part of the medium under study and determine its speed characteristic by the diffracted wave.

Способ осуществляется следующим образом.The method is as follows.

На земной поверхности располагают расстановку сейсмоприемников, проходящую вблизи устья скважины.On the earth's surface there is an arrangement of geophones, passing near the wellhead.

В скважину, заполненную жидкостью, в интервал глубин, неблагоприятный для проведения взрывов, помещают нижний конец колонны бурильных труб. На забой скважины через колонну труб опускают заряд ВВ. Проводят взрыв заряда и регистрацию дифрагированной волны.In the well, filled with fluid, in the depth interval, unfavorable for explosions, put the lower end of the drill pipe string. At the bottom of the well through the pipe string lower explosive charge. A charge explosion and registration of a diffracted wave are carried out.

Ззтем нижний конец колонны труб помещают на следующую глубину в выбранном интервале. На забой скважины снова опускают заряд ВВ. Проводят взрыв и регистрацию на земной поверхности дифрагированной волны отнижнего конца колонны труб. Процесс перемещения колонны бурильных труб и регистрации дифрагированных волн повторяется в зависимости от требуемой детальности изучения покрывающей толщи.Then the lower end of the pipe string is placed at the next depth in the selected interval. The explosive charge is again lowered to the bottom of the well. Explosion and registration are carried out on the earth's surface of the diffracted wave of the lower end of the pipe string. The process of moving the drill string and recording diffracted waves is repeated depending on the required detail of the study of the overburden.

II

В качестве примера реализации рассматривается использование способа на Шуртанской площади по повышению детальности изучения покрывающей толщи, содержащей интервалы разреза верейского и визейского возрастов, сложенных сыпучими терригенными породами и залегающих на глубинах 1200 и 1650 м соответственно, и непригодных для проведения взрывов из-за опас ности обвалов и ликвидации скважины.As an example of implementation, we consider the use of the method on Shurtanskaya Square to increase the detail of studying the overburden, containing intervals of the Verey and Visean ages, composed of loose terrigenous rocks and occurring at depths of 1200 and 1650 m, respectively, and unsuitable for explosions because of the risk of collapses and well liquidation.

В скважину, заполненную буровым раствором, на забой, находящийся на глубине 2000 м, помещают заряд ВВ весом 5,2 кг. Проводят взрыв и регистрацию упругих колебаний на земной поверхности расстановкой сейсмоприемников длиной 1200 м.In a well filled with drilling fluid, an explosive charge weighing 5.2 kg is placed on a face located at a depth of 2000 m. Explosion and registration of elastic vibrations on the earth's surface is carried out by the arrangement of geophones 1200 m long.

В эту же скважину спускают колонну бурильных труб и нижний конец помещают на глубину 1650 м, затем ниже на забой скважины на глубину 2000 м помещают заряд 5,2 кг. Проводят взрыв и регистрацию упругих колебаний на земной поверхности той же расстановкой сейсмоприемников.A drill pipe string is lowered into the same well and the lower end is placed at a depth of 1650 m, then a charge of 5.2 kg is placed below the bottom of the well at a depth of 2000 m. An explosion and registration of elastic vibrations on the earth's surface is carried out by the same arrangement of geophones.

Затем нижний конец колонны бурильных труб помещают на глубину 120Q м, на забой скважины на глубину 2000 м снова помещают заряд 5,2 кг. Проводят взрыв и регистрацию упругих колебаний на земной поверхности той же расстановкой сейсмоприемников.Then the lower end of the drill pipe string is placed at a depth of 120Q m, a 5.2 kg charge is again placed at the bottom of the well at a depth of 2000 m. An explosion and registration of elastic vibrations on the earth's surface is carried out by the same arrangement of geophones.

На сейсмограмме, полученной от первого взрыва, наблюдаются волны от одного взрывного источника колебаний, расположенного на глубине 2000 м, которые позволяют изучать сплошной интервал разреза мощностью 2000 м, включающий покрывающую толщу от земной поверхности до забоя скважины. Дифрагированные волны не зарегистрированы .The seismogram obtained from the first explosion shows waves from one explosive oscillation source located at a depth of 2000 m, which allows one to study the continuous interval of a section with a thickness of 2000 m, including the covering stratum from the earth's surface to the bottom of the well. Diffracted waves are not registered.

На сейсмограмме, полученной от второго взрыва, дополнительно к волнам от взрывного источника на забое скважины зарегистрирована дифрагированная волна от нижнего конца колонны бурильных труб, помещенного на глубину 1650 м в терригенные породы визейского возраста, которая позволяет изучать еще один интервал разреза мощностью 1650 м, включающий покрывающую толщу от земной поверхности до глубины 1650 м. Кроме того, появилась возможность для изучения интервала разреза, залегающего между забоем скважины и глубиной 1650 м.On the seismogram obtained from the second explosion, in addition to the waves from the blasting source, a diffracted wave from the lower end of the drill pipe string, placed at a depth of 1650 m in terrigenous rocks of the Visean age, is recorded, which allows one to study another section interval with a thickness of 1650 m, including covering the thickness from the earth's surface to a depth of 1650 m. In addition, it became possible to study the interval of the section between the bottom of the well and a depth of 1650 m.

На сейсмограмме, полученной от третьего взрыва, дополнительно к волнам от взрывного источника на забое скважины зарегистрирована дифрагированная волна от нижнего конца, колонны бурильных труб, помещенного на глубину 1200 м в терригенные породы верейского возраста, которая позволяет изучить еще один интервал разреза мощностью 1200 м, включающий покрывающую толщу от земной поверхности до глубины 1200 м. Одновременно появляется возможность для изучения интервала разреза, залегающего между забоем скважины и глубиной 1200 м.On the seismogram obtained from the third explosion, in addition to the waves from the blasting source, a diffracted wave from the lower end, drill pipe strings located at a depth of 1200 m in terrigenous rocks of the Vereian age, is recorded in addition to waves from the bottom end of the borehole, which allows one more section to be studied with a thickness of 1200 m, including the covering stratum from the earth's surface to a depth of 1200 m. At the same time, it becomes possible to study the interval of the section between the bottom of the well and a depth of 1200 m.

Положительный эффект получается за счет повышения детальности изучения пород геологического разреза, содержащих интервалы, неблагоприятные для производства взрывов.A positive effect is obtained by increasing the detail of studying the rocks of the geological section containing intervals unfavorable for the production of explosions.

Claims

The invention relates to seismic exploration using boreholes and can be used in prospecting and exploration of oil and gas and other mineral deposits. The known method of seismic exploration is based on sequentially initiating elastic oscillations at different depths below sharp boundaries and registering them with receivers installed on the ground 1. The disadvantage of this method is the impossibility of placing the charge before explosives explosives and conducting explosions around the wellbore in the interval cuts formed by loose terrigenous rocks due to the danger of creating collapses, blockage and abandonment of the well. The closest technical solution to the invention is a seismic exploration method based on the excitation of vibrations in a well, a polishing fluid, explosive charges, and recording on the earth's surface diffracted waves caused by artificial inhomogeneities located in a well.

2. The disadvantage of this method is that it is impossible to carry out the winds on the sections of the non-de-oriented casing string, which is accompanied by the deformation of the string, 3ef closure and the elimination of the well. In addition, the depth of immersion of explosive charge and the size of the interval of the overburden studied is limited by the length of the casing. The aim of the invention is to increase the detail of the study of the structure of intervals that are unsuitable for conducting excitation of vibrations. This goal is achieved by the fact that according to the seismic survey method, based on the excitation of oscillations in a well filled with fluid, explosive charges, and recording on the earth's surface diffracted will caused by art inks inhomogeneities, located in the well, as an artificial heterogeneity located in squigikine use the lower part of the string of drill pipe, for to the 1 st position, which in the interval of studies is carried out the oscillation at the bottom of the well iny. The essence of the method is as follows. Oscillations excited at the bottom of the well, reaching the bottom of the drill string, are converted into diffracted waves, which are recorded on the earth's surface. By moving the drill string along the surface trunk, you can place the source of the diffracted waves in any part of the medium under study and determine its velocity through the diffracted wave characteristic. The method is carried out as follows. On the earth's surface there is an arrangement of seismic receivers passing near the wellhead. In the well filled with liquid in the depth range, which is unfavorable for explosions, the lower end of the drill pipe is placed. At the bottom of the well, the explosive charge is lowered through the pipe. The charge is detonated and a diffracted wave is recorded. Here the lower end of the pipe string is placed to the next depth in the selected interval. At the bottom of the well, the explosive charge is lowered again. Conducted an explosion and registration on the earth's surface of the diffracted wave of the lower end of the pipe string. The process of moving the drill string and recording the diffracted waves is repeated, depending on the required study details covering the strata. As an example of implementation, use is made of the method on the Shurtan area to increase the detail of the study of the overlying stratum containing intervals of cut of the Vereisk and Visean ages composed of loose terrigenous rocks and occurring at depths of 120 and 1650 m, respectively, and unsuitable for conducting explosions due to collapse and well abandonment A well filled with a drilling fluid weighing 5.2 kg is placed on a well filled with drilling mud at a bottomhole located at a depth of 2000 m. An explosion and registration of elastic oscillations on the earth's surface by seismic seismic receivers with a length of 1200 m are carried out. A drill string is lowered into the same well and the lower end of the well is placed at a depth of 1650 m, then the charge is placed at the bottom of the well at a depth of 2000 m 5.2 kg. An explosion and the recording of elastic oscillations on the earth's surface are carried out by the same arrangement of seismic receivers. Then, the lower end of the drill pipe string will be placed at a depth of 120Q m, and a charge of 5.2 kg is placed on the bottom of the well at a depth of 2000 m. An explosion and the recording of elastic oscillations on the earth's surface are carried out by the same arrangement of seismic receivers. On the seismogram obtained from the first explosion, waves are observed from a single source of oscillations located at a depth of 2000 m, which allow studying a continuous interval of 2000 m, including 1; Diffracted waves are not recorded. In the seismogram obtained from the second explosion, in addition to the waves from the explosive source, a diffracted wave was recorded at the bottom of the well from the lower end of the drill pipe string, placed at a depth of 1650 m in terrigenous rocks of Visean age, which allows one intern to study; a section with a capacity of 1650 m, including the overlying thickness from the earth’s surface to a depth of 1650 m. In addition, it was possible to study the interval of the section between the bottom hole and 1650 m depth. On the third explosion, in addition to the waves from an explosive source at the bottom of the well recorded a diffracted wave from the lower end, a string of drill pipes placed at a depth of 1200 m into terrigenous rocks of the Vereian age, which allows studying another interval of a 1200-m cut, including a covering thickness from the earth's surface to a depth of 1200 m. At the same time, it becomes possible to study the interval of the section between the bottom of the well and 1200 m. The positive effect is obtained by increasing the detail of studying geological sections of rocks that are unfavorable for the production of explosions. . The invention The seismic exploration method, based on the excitation of oscillations in a well filled with fluid, explosive charges, and recording of diffracted waves on the earth's surface caused by art inhomogeneities located in the well, lt h and h. so that, in order to increase the detail of the study of the structure of intervals that are unfavorable for the conduct of excitation of oscillations.

5.1002996

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for each position 363951, cl, G 01 V1 / 40, 1971. which in the range of studies is 2. Halperin E.I. Vertical

water m vibration excitation at the bottom of the seismic profiling. M.,

wells. Nedra, 1971, p. 23 (prototype).