CN104950327A - Method for determining positions of geophones of ground microseismic observation system - Google Patents

Abstract

The invention provides a method for determining the positions of geophones of a ground microseismic observation system. The method comprises the following steps: (a), acquiring existing files of a work area and establishing a geologic model; (b), performing fracture simulation to obtain the transverse range affected by reservoir fracturing fracture waves according to the geologic model, the depth of a target stratum and the fracturing construction scale; (c), determining the laying range of the geophones according to the transverse range affected by the reservoir fracturing fracture waves, the depth of the target stratum and microseismic signal wavelengths; (d), determining track intervals according to the microseismic signal wavelengths; (e), determining the laying coordinates of each geophone according to wellhead coordinates, the laying range of the geophones and the track intervals. According to the embodiment of the invention, the ground microseismic observation system is designed through integration of related monitoring task information such as parameters of the fracturing construction scale, geologic features of the target stratum and the like, high-quality fracturing seismic signals can be obtained economically and effectively, and the method is economic and practical.

Description

Determine the method for the position of the wave detector of ground micro-seismic recording geometry

Technical field

All things considered of the present invention relates to the technical field of seismic prospecting, more particularly, relates to a kind of method of position of wave detector of the ground micro-seismic recording geometry for zone of interest.

Background technology

Reservoir fracturing is one of low-permeability reservoir important means realizing high yield, microseismic be in current reservoir fracturing process the most accurately, the most in time, monitoring means that information is the abundantest.Ground micro-seismic monitoring, shallow well micro-seismic monitoring, deep-well micro-seismic monitoring is divided into according to the microseismic of the installation position of wave detector.

Deep-well micro-seismic monitoring needs string to be arranged in a bite monitor well near fractured well, and monitor well distance is comparatively large on monitoring effect impact, and exploratory development initial stage well is few, so apply limited.Shallow well micro-seismic monitoring needs to bore 3-5 mouth shallow well in fractured well week, and construction cost is higher and the early-stage preparations time is long.Ground micro-seismic monitoring is the microearthquake signal by receiving rock burst release in fracturing process at surface deployment wave detector, determines a kind of method of Oil/gas Well waterfrac treatment fracture morphology, is more and more applied in the production practices of at home and abroad oil gas field.Micro-seismic monitoring result can determine fracture distribution geometric shape and space characteristics, for evaluating reservoir fracturing improvement effect.

Ground micro-seismic monitoring execution conditions require low, but waterfrac treatment rock burst microearthquake signal energy is weak, is subject to the various disturbing effect of earth-attenuation and ground, has higher requirement to signals collecting.Therefore the decision design of recording geometry is directly connected to the reliability of ground micro-seismic monitoring, and current ground micro-seismic monitoring recording geometry design specific aim is not strong, and the ground micro-seismic quality of data of acquisition is not high.

In recent years, along with deepening continuously of Sichuan shale gas exploratory development, ground micro-seismic Monitoring Service market increases, waterfrac treatment rock burst microearthquake signal is effectively obtained in order to economy, accurate description fracturing artificial slit form and evaluation reservoir volume correctional effect, be badly in need of a kind of microearthquake recording geometry method for designing that can obtain the ground micro-seismic data of high-quality.

Summary of the invention

Exemplary embodiment of the present invention is the method for the position of the wave detector providing a kind of ground micro-seismic recording geometry for zone of interest, the problem that the ground micro-seismic quality of data that the recording geometry that can solve existing method design obtains is not high.

Exemplary embodiment of the present provides a kind of method determining the position of the wave detector of the ground micro-seismic recording geometry for zone of interest, comprising: (a) obtains the existing data in work area, sets up geologic model; B (), according to described geologic model, the zone of interest degree of depth and pressing crack construction scale, carries out fracture simulation, obtain the lateral extent that reservoir fracturing crack is involved; The laying scope of c lateral extent, the zone of interest degree of depth and microearthquake signal wavelength determination wave detector that () is involved according to reservoir fracturing crack; D () is according to microearthquake signal wavelength determination track pitch; E () determines the laying coordinate of each wave detector according to the laying scope of mouth coordinate, wave detector and track pitch.

Alternatively, step (b) comprises, according to described geologic model, the zone of interest degree of depth and pressing crack construction scale, carry out fracture simulation to obtain the length in liquid crack, by take well head as the center of circle, the region that comprises of the half of the length in the liquid crack circle that is radius is defined as the lateral extent that involves in reservoir fracturing crack.

Alternatively, step (c) comprises, picture aperture is specified to according to the zone of interest degree of depth and microearthquake signal wavelength, multiple point is got on the border of the lateral extent involved in described reservoir fracturing crack equably, with each point in described multiple point for the center of circle, with imaging aperture for radius draws circle, the region at the union place of the circle of all pictures is defined as the laying scope of wave detector.

Alternatively, the size in imaging aperture meets and makes the lowest frequency signal of microearthquake at least reach half microearthquake signal wavelength from the focus zone of interest to from the nearest wave detector of described focus with from the difference of the stroke of described focus wave detector farthest.

Alternatively, in step (c), be specified to picture aperture according to following formula:

$p=\sqrt{{(d+{\mathrm{\λ}}_{max}/2)}^2-d^2},$

Wherein, p is expressed as picture aperture, and d represents the zone of interest degree of depth, λ _maxrepresent the most long wavelength of microearthquake signal.

Alternatively, the size of described track pitch meets and makes the most high-frequency signal of microearthquake all be not more than half microearthquake signal wavelength from the focus zone of interest to the difference of any two adjacent wave detector strokes.

Alternatively, the size of described track pitch is the half of microearthquake signal minimal wave length.

Alternatively, in step (e), determine the laying coordinate of any one wave detector according to following formula:

$x_{ij}=g\×j\×cos\left(\right(90-\frac{360\×i}{m})\×\frac{\mathrm{\π}}{180})+x,$

$y_{ij}=g\×j\×sin\left(\right(90-\frac{360\×i}{m})\×\frac{\mathrm{\π}}{180})+y,$

Wherein, (x _ij, y _ij) represent the coordinate of a jth wave detector on the i-th line, i ∈ [1, m], j ∈ [1, n _i], m represents the number of buses of wave detector, n _irepresent the quantity of the wave detector on i-th line, g represents track pitch, and (x, y) represents the coordinate of well head.

Determine according to an exemplary embodiment of the present invention the ground micro-seismic recording geometry for zone of interest wave detector position method in, the monitoring mission bit stream combining the parameter of pressing crack construction scale, zone of interest geologic feature etc. relevant designs ground micro-seismic recording geometry, the pressure break that can obtain high-quality is cost-effectively broken microearthquake signal, for determining that fracturing artificial slit form and reservoir volume correctional effect are laid a good foundation.And owing to only considering the lateral extent involved in reservoir fracturing crack in computation process, do not consider the parameter such as longitudinal extent and frac pressure, so economical and practical.

Accompanying drawing explanation

By below in conjunction with exemplarily illustrating the description that the accompanying drawing of embodiment carries out, the above and other object of exemplary embodiment of the present and feature will become apparent, wherein:

Fig. 1 illustrates the process flow diagram of the method for the position of the wave detector of the ground micro-seismic recording geometry determined according to an exemplary embodiment of the present invention for zone of interest;

Fig. 2 illustrates the schematic diagram of the scope that the reservoir fracturing crack that fracture simulation produces according to an exemplary embodiment of the present invention is involved;

Fig. 3 illustrates the schematic diagram of the laying scope of wave detector according to an exemplary embodiment of the present invention.

Embodiment

Now will in detail with reference to exemplary embodiment of the present invention, the example of described embodiment is shown in the drawings, and wherein, identical label refers to identical parts all the time.Below by referring to accompanying drawing, described exemplary embodiment will be described, to explain the present invention.

Fig. 1 illustrates the process flow diagram of the method for the position of the wave detector of the ground micro-seismic recording geometry determined according to an exemplary embodiment of the present invention for zone of interest.

With reference to Fig. 1, in step S10, obtain the existing data in work area, set up geologic model.Here, the existing data in work area can comprise following at least one: comprise drilling data, well-log information, geologic information etc.It will be understood by those skilled in the art that by the existing data in work area to build Stratigraphic framework and to obtain the information such as formation velocity, density, Rock Elastic Parameters, thus set up geologic model.

In step S20, according to described geologic model, the zone of interest degree of depth and pressing crack construction scale, carry out fracture simulation, obtain the lateral extent that reservoir fracturing crack is involved.Described pressing crack construction scale is pre-set data, such as, can comprise the data such as infusion program, discharge capacity, sand concentration, liquid volume, sand body be long-pending.The scope that described reservoir fracturing crack is involved is generally spheroid, and the lateral extent that described reservoir fracturing crack is involved is the described spheroid face crossing with described zone of interest.Here, in fracture simulation software, the relevant parameter such as described geologic model, the zone of interest degree of depth and pressing crack construction scale can be inputted to carry out fracture simulation.

In step S20, fracture simulation can be carried out to obtain the length in liquid crack, by take well head as the center of circle, the region that comprises of the half of the length in the liquid crack circle that is radius is defined as the lateral extent that involves in reservoir fracturing crack.Described well head refers to the well head of perpendicular hole.In fracture simulation software, inputting described geologic model, the zone of interest degree of depth and pressing crack construction scale, (such as liquid volume is 1500 sides, it is 70 sides etc. that sand body amasss) etc. relevant parameter carry out fracture simulation after the scope 2 that will obtain as shown in Figure 2 fracture simulation produces according to an exemplary embodiment of the present invention reservoir fracturing crack and involve, the length L in described liquid crack is 380 meters, the lateral extent that reservoir fracturing crack is involved be with perpendicular hole 1 the pithead position 4 of objective interval 3 be the center of circle, the region that comprises of the half of the length L in the liquid crack circle that is radius.

In step S30, according to the laying scope of lateral extent, the zone of interest degree of depth and microearthquake signal wavelength determination wave detector that reservoir fracturing crack is involved.Here, the laying scope of wave detector refers to the geographic range laying wave detector on the ground.The laying scope of the lateral extent involved according to reservoir fracturing crack by various suitable mode, the zone of interest degree of depth and microearthquake signal wavelength determination wave detector.Such as, can the laying scope of wave detector according to an exemplary embodiment of the present invention as shown in Figure 3, first can be specified to picture aperture r according to the zone of interest degree of depth and microearthquake signal wavelength, four points 5 are got on the border of the lateral extent involved in described reservoir fracturing crack equably, with each point 5 in described four points 5 for the center of circle, with imaging aperture for radius r draws four circles, the region at the union place of described four circles is defined as the laying scope of wave detector.It will be understood by those skilled in the art that the quantity of the point got on the border of lateral extent is not limited to four, can also be other quantity.

Here, the size in described imaging aperture meets and makes the lowest frequency signal of microearthquake at least reach half microearthquake signal wavelength from the focus zone of interest to from the nearest wave detector of described focus with from the difference of the stroke of described focus wave detector farthest.Described imaging aperture is determined by following formula (1).

$p=\sqrt{{(d+{\mathrm{\λ}}_{max}/2)}^2-d^2}---\left(1\right)$

Wherein, p is expressed as picture aperture, and d represents the zone of interest degree of depth, λ _maxrepresent the most long wavelength of microearthquake signal.It will be understood by those skilled in the art that the account form in imaging aperture is according to an exemplary embodiment of the present invention not limited to the mode of formula (1), picture aperture can also be specified to by other suitable modes.

In step S40, according to microearthquake signal wavelength determination track pitch.Here, described track pitch refers on same line between adjacent wave detector distance.The size of described track pitch need meet makes the most high-frequency signal of microearthquake all be not more than half microearthquake signal wavelength from the focus zone of interest to the difference of any two adjacent wave detector strokes.In order to simplify calculating, the size of described track pitch can be defined as the half of microearthquake signal minimal wave length.

It will be understood by those skilled in the art that the step numbers of step S30 and step S40 is not used in restriction execution sequence, any one step in these two steps can first perform.

In step S50, determine the laying coordinate of each wave detector according to the laying scope of mouth coordinate, wave detector and track pitch.Described mouth coordinate is the coordinate of perpendicular hole on ground.

Alternatively, in S step 50, the laying coordinate of any one wave detector can be determined according to formula (2) and (3):

$x_{ij}=g\×j\×cos\left(\right(90-\frac{360\×i}{m})\×\frac{\mathrm{\π}}{180})+x---\left(2\right)$

$y_{ij}=g\×j\×sin\left(\right(90-\frac{360\×i}{m})\×\frac{\mathrm{\π}}{180})+y---\left(3\right)$

Wherein, (x _ij, y _ij) represent the laying coordinate of a jth wave detector on the i-th line, i ∈ [1, m], j ∈ [1, n _i], m represents the number of buses of wave detector, n _irepresent the quantity of the wave detector on i-th line, g represents track pitch, and (x, y) represents the coordinate of well head.Here, the number of buses m of wave detector is the data pre-set.Article i-th, the quantity n of the wave detector on line _ibe the business that the spread length of the wave detector of i-th line obtains divided by track pitch, the spread length of the wave detector of described i-th line can according to the position angle of described i-th line determine with the laying scope of described wave detector.

It will be understood by those skilled in the art that the account form of the laying coordinate of wave detector is according to an exemplary embodiment of the present invention not limited to the mode of formula (2) and (3), can also be determined by other suitable modes.

After the laying coordinate having determined the wave detector on every bar line, the parameter that in ground micro-seismic recording geometry, wave detector is relevant can be exported, as the laying coordinate etc. of geophone arrangement length, track pitch, wave detector sum, wave detector.

Determine according to an exemplary embodiment of the present invention the ground micro-seismic recording geometry for zone of interest wave detector position method in, the monitoring mission bit stream combining the parameter of pressing crack construction scale, zone of interest geologic feature etc. relevant designs ground micro-seismic recording geometry, the pressure break that can obtain high-quality is cost-effectively broken microearthquake signal, for determining that fracturing artificial slit form and reservoir volume correctional effect are laid a good foundation, economical and practical.

Can be used to according to the said method of exemplary embodiment of the present invention the equipment designed for the ground micro-seismic recording geometry of zone of interest realize, also may be implemented as computer program, thus when running this program, realize said method.

Although show and described exemplary embodiments more of the present invention, but those skilled in the art should understand that, when not departing from by the principle of the present invention of claim and its scope of equivalents thereof and spirit, can modify to these embodiments.

Claims (8)

1. determine a method for the position of the wave detector of the ground micro-seismic recording geometry for zone of interest, it is characterized in that, comprising:

A () obtains the existing data in work area, set up geologic model;

B (), according to described geologic model, the zone of interest degree of depth and pressing crack construction scale, carries out fracture simulation, obtain the lateral extent that reservoir fracturing crack is involved;

The laying scope of c lateral extent, the zone of interest degree of depth and microearthquake signal wavelength determination wave detector that () is involved according to reservoir fracturing crack;

D () is according to microearthquake signal wavelength determination track pitch;

E () determines the laying coordinate of each wave detector according to the laying scope of mouth coordinate, wave detector and track pitch.

2. method according to claim 1, it is characterized in that, step (b) comprises, according to described geologic model, the zone of interest degree of depth and pressing crack construction scale, carry out fracture simulation to obtain the length in liquid crack, by take well head as the center of circle, the region that comprises of the half of the length in the liquid crack circle that is radius is defined as the lateral extent that involves in reservoir fracturing crack.

3. method according to claim 1, it is characterized in that, step (c) comprises, picture aperture is specified to according to the zone of interest degree of depth and microearthquake signal wavelength, multiple point is got on the border of the lateral extent involved in described reservoir fracturing crack equably, with each point in described multiple point for the center of circle, with imaging aperture for radius draws circle, the region at the union place of the circle of all pictures is defined as the laying scope of wave detector.

4. defining method according to claim 3, it is characterized in that, the size in imaging aperture meets makes the lowest frequency signal of microearthquake at least reach half microearthquake signal wavelength from the focus zone of interest to from the nearest wave detector of described focus with from the difference of the stroke of described focus wave detector farthest.

5. method according to claim 4, is characterized in that, in step (c), is specified to picture aperture according to following formula:

$p=\sqrt{{(d+{\mathrm{\λ}}_{max}/2)}^2-d^2},$

Wherein, p is expressed as picture aperture, and d represents the zone of interest degree of depth, λ _maxrepresent the most long wavelength of microearthquake signal.

6. method according to claim 1, is characterized in that, the size of described track pitch meets makes the most high-frequency signal of microearthquake all be not more than half microearthquake signal wavelength from the focus zone of interest to the difference of any two adjacent wave detector strokes.

7. method according to claim 6, is characterized in that, the size of described track pitch is the half of microearthquake signal minimal wave length.

8. method according to claim 1, is characterized in that, in step (e), determines the laying coordinate of any one wave detector according to following formula:

$x_{ij}=g\×j\×cos\left(\right(90-\frac{360\×i}{m})\×\frac{\mathrm{\π}}{180})+x,$

$y_{ij}=g\×j\×sin\left(\right(90-\frac{360\×i}{m})\×\frac{\mathrm{\π}}{180})+y,$

Wherein, (x _ij, y _ij) represent the coordinate of a jth wave detector on the i-th line, i ∈ [1, m], j ∈ [1, n _i], m represents the number of buses of wave detector, n _irepresent the quantity of the wave detector on i-th line, g represents track pitch, and (x, y) represents the coordinate of well head.