CN104504182A - Method for rapidly identifying unconventional gas reservoir - Google Patents

Abstract

The invention discloses a method for rapidly identifying an unconventional gas reservoir. The method comprises the following steps: a, collecting and arranging logging engineering parameters and geological parameters of a target layer; b, calculating a logging clay index MLCF by utilizing the logging engineering parameters and the geological parameters; c, calculating a drilled stratum free gas content index MLGA by utilizing the logging engineering parameters and the geological parameters; d, producing an MLCF-MLGA crossplot by utilizing the calculated logging clay index MLCF and the drilled stratum free gas content index MLGA; e, rapidly identifying the development situation of the unconventional reservoir by utilizing the MLCF-MLGA crossplot. By adopting the method, the advantages of the logging-while-drilling technology such as timeliness, high efficiency, truth and rapidness can be realized, the logging engineering and geological parameters are comprehensively utilized, and the development situation of the compact gas reservoir can be rapidly identified.

Description

Unconventional gas reservoir reservoir knows method for distinguishing fast

Technical field

The present invention relates to a kind of unconventional gas reservoir reservoir and know method for distinguishing fast, belong to electro-mechanical arts industrial gas oil exploratory development category with brill log data treatment technology application.

Background technology

Unconventional forage refers to that hydro carbons (or non-hydrocarbons) the resource Unconventional forage being different from conventional gas in reservoiring mechanism, occurrence status, the regularity of distribution or exploratory development mode etc. mainly comprises compact sandstone gas, coal-seam gas, shale gas etc., China's unconventional petroleum resources is very abundant, and development unconventional energy resource all has important strategic importance to guarantee national energy security, environmental protect, safe coal production, solution agriculture, rural areas and farmers (agricultural, rural area, peasant) problem etc.

The burnt masonry dam in Fuling, just obtaining effect indicates shale gas in the shale gas explorations such as Changning, Yibin, the fine and close lithologic gas reservoirs exploratory development that compact sandstone gas etc. are representative enters a new stage, " energy is taken over, transition and upgrade " be achievements and the reality need of CNPC's industry, the large step in current domestic each major oil company forward unconventionaloil pool field advances, but the domestic conventional oil Resources Strategy of China is taken over exists difficulty, most of oil field, land east has entered exploitation middle and advanced stage, more than water outlet is fuel-displaced, although central and west regions petroleum reserves is larger, but investment is large, technical sophistication, degree of prospecting is not high, and unconventional gas reservoir understanding urgently deeply, logging explanation technology is started from scratch especially, at present, hide exploratory development for unconventionaloil pool and mainly there is following problem at present:

1, stratum storage and collection performance is usually poor, and someone thinks that shale gas is composed and is stored in ultralow hole, Oil in Super-low Permeability Reservoirs, and aperture can be low to moderate nanoscale, and this is to traditional reservoiring theory and explain that assessment technique proposes powerful challenge.

2, unconventional reservoiring theory is not yet reached common understanding, there is certain difference: at present carried out a series of relevant unconventionaloil pool around this focal issue of shale gas reservoir reservoiring theory in the industry and hidden tax and deposit and the fierceness discussion of the supporting geological theory of exploratory development, how to utilize external experience successful implantation in advance to domestic exploratory development theoretical research and exploration practices, how effectively to determine effective unconventionaloil pool reservoir fast, how to realize these problems of unification of engineering geology target and there is no final conclusion, urgently more profound, the theory innovation of wider aspect and actual practicing.

3, logging explanation technology not yet starts to walk: current most logging explanation method adopts statistical method, the difference of employing layer position, well data, even equipment all can cause significant impact to statistics and conclusion, new well has been had to change statistical model often, cannot prospect pit apply in early days, and other a part of method man's activities are serious, explanation results even may be caused seriously unfounded, the objectivity of conclusion cannot be guaranteed.

Summary of the invention

The object of the invention is to the problems referred to above overcoming prior art existence, provide a kind of unconventional gas reservoir reservoir to know method for distinguishing fast.The present invention play well logging interpretation while drilling in time, efficiently, truly, advantage fast, integrated use well logging engineering and geologic parameter, identify fast to fine and close lithologic gas reservoirs reservoir development situation.

For achieving the above object, the technical solution used in the present invention is as follows:

A kind of unconventional gas reservoir reservoir knows method for distinguishing fast, it is characterized in that, comprises the steps:

A, compile zone of interest well logging engineering parameter and geologic parameter;

B, well logging engineering parameter and geologic parameter is utilized to calculate well logging clay index M LCF;

C, well logging engineering parameter and geologic parameter is utilized to calculate drilling strata free gas content index M LGA;

D, utilize the well logging clay index M LCF that calculates and drilling strata free gas content index M LGA, make MLCF ?MLGA X plot;

E, utilize MLCF ?MLGA X plot unconventional gas reservoir reservoir development situation is identified fast.

In described step a, well logging engineering parameter and geologic parameter comprise the zone of interest of comprehensive logging instrument record with brill drilling fluid performance parameters, in real time logging data, late logging data.

In described step b, MLCF computing method are as follows:

MLCF=lg[(0.002π) ²·(dbit) ²·(RPM) ²·(60·ROP) ²/WOB/(0.001·dbit)·ROP·60]

Wherein MLCF---well logging stratum clay content index;

RPM---drilling speed, r/min;

WOB---the pressure of the drill, kN;

ROP---rate of penetration, h/m;

Dbit---bit diameter, mm.

In described step b, reservoir exploitation is used to the situation of waterpower screw rod, because drill bit true drilling speed in shaft bottom is difficult to measure, therefore each brill tooth of setting MLCF calculating outer rim singly turns average power ratio at every turn;

That is,

MLCF=lg[(0.002π) ²·(dbit) ²·(60·ROP) ²/WOB/(0.001·dbit)·ROP·60]。

In described step c, adopt drilling well liquid hydrocarbon component to characterize as reservoir oil-gas possibility is approximate, introduce well logging drilling fluid hydrocarbon components variation index (MLGA) its computing method as follows:

MLGA＝(M-Aver(M))/(60·σM·ROP·WOB)

Wherein: MLGA---well logging drilling fluid hydrocarbon components variation index, is called for short hydrocarbon resistivity index;

M---light hydrocarbon component and heavy hydrocarbon component percentage composition, read value according to chromatogram, dimensionless;

Aver (M)---mean function;

σ M---light hydrocarbon component and heavy hydrocarbon component percentage composition standard deviation;

ROP---during brill, h/m;

WOB---the pressure of the drill, kN.

In described steps d, create MLCF data track and MLGA data track respectively, its separately data track range establishing method be: setting MLCF and MLGA road is M road, road to be placed, and corresponding data codomain is (m, n), Ze Tu road range arranges rule and can be expressed as:

(-min(abs(m),abs(n),min(abs(m),abs(n))

Wherein, min (x, y) is the function differentiating minimum value in x, y, and abs (x) is ABS function;

And combine MLCF data track and MLGA data track make MLCF ?MLGA X plot.

In described step e, its recognition method is: the rising of MLCF index (rising of clay mineral content), MLGA index decreased (stratum hydrocarbonaceous amount is few), then sign corresponding well dark drilling strata (hydrocarbonaceous) reservoir is owed and is educated, (clay mineral content reduces MLCF index decreased, brittle mineral content raise), MLGA index rise (stratum hydrocarbonaceous amount increase, the content of organic matter improves), and both have intersection on figure road, then characterize corresponding well dark drilling strata (hydrocarbonaceous) reservoir and comparatively grow.

Employing the invention has the advantages that:

One, the present invention play well logging interpretation while drilling in time, efficiently, truly, advantage fast, integrated use well logging engineering and geologic parameter, high level overview and system summary unconventionaloil pool hide the positive connection existed between the necessity of logging parameters in exploratory development process and reservoir and hole condition feature, set up shaft bottom, well head well logging engineering and geologic parameter MLCF ?MLGA X plot, by logging parameters reprocessing and interpretation technique, realize geological theory, engineering decision powerful support.

Two, the present invention has the advantage of fast and reliable, can realize more reliably utilizing logging parameters identification unconventional gas reservoir reservoir.

Three, the present invention has the advantage of simple and effective, summarizes and refines the effective information obtaining data in well logging process, processing speed is fast, process control, being convenient to implement.

Four, the present invention has all-embracing advantage, and while fully paying close attention to geology oil accumulation factor, comprehensive consideration volume increase construction factor, practices Geological Engineering integration thinking.

Five, the present invention extensively can be adapted to the unconventional gas reservoir RESERVOIR RECOGNITION such as tight gas, shale gas on noncarbonate rock stratum, obtains better effect at present in Weiyuan, sichuan gas field and the application of area, Changning.

Accompanying drawing explanation

Fig. 1 be MLCF of the present invention ?MLGA crossplot schematic diagram

Fig. 2 is process flow diagram of the present invention

Fig. 3 is that bit cutting creeps into ideal model schematic diagram

Fig. 4 is the stressed schematic diagram of drill bit outer rim monodentate

Embodiment

Embodiment 1

A kind of unconventional gas reservoir reservoir knows method for distinguishing fast, comprises the steps:

A, compile zone of interest well logging engineering parameter and geologic parameter;

B, well logging engineering parameter and geologic parameter is utilized to calculate well logging clay index M LCF;

C, well logging engineering parameter and geologic parameter is utilized to calculate drilling strata free gas content index M LGA;

D, utilize the well logging clay index M LCF that calculates and drilling strata free gas content index M LGA, make MLCF ?MLGA X plot;

E, utilize MLCF ?MLGA X plot unconventional gas reservoir reservoir development situation is identified fast.

In described step a, well logging engineering parameter and geologic parameter comprise the zone of interest of comprehensive logging instrument record with brill drilling fluid performance parameters, in real time logging data, late logging data.Wherein, engineering parameter comprises: during brill, drilling speed, bit diameter, the pressure of the drill; The geologic parameter of well logging engineering admission comprises: hydrocarbon value, comprises the organic component such as total hydrocarbon, methane content.

In described step b, MLCF computing method are as follows:

MLCF=lg[(0.002π) ²·(dbit) ²·(RPM) ²·(60·ROP) ²/WOB/(0.001·dbit)·ROP·60]

Wherein MLCF---well logging stratum clay content index;

RPM---drilling speed, r/min;

WOB---the pressure of the drill, kN;

ROP---rate of penetration, h/m;

Dbit---bit diameter, mm.

In described step b, reservoir exploitation is used to the situation of waterpower screw rod, because drill bit true drilling speed in shaft bottom is difficult to measure, therefore each brill tooth of setting MLCF calculating outer rim singly turns average power ratio at every turn, that is:

MLCF=lg[(0.002π) ²·(dbit) ²·(60·ROP) ²/WOB/(0.001·dbit)·ROP·60]。

In described step c, adopt drilling well liquid hydrocarbon component to characterize as reservoir oil-gas possibility is approximate, introduce well logging drilling fluid hydrocarbon components variation index (MLGA) its computing method as follows:

MLGA＝(M-Aver(M))/(60·σM·ROP·WOB)

Wherein: MLGA---well logging drilling fluid hydrocarbon components variation index, is called for short hydrocarbon resistivity index;

M---light hydrocarbon component and heavy hydrocarbon component percentage composition, read value according to chromatogram, dimensionless;

Aver (M)---mean function;

σ M---light hydrocarbon component and heavy hydrocarbon component percentage composition standard deviation;

ROP---during brill, h/m;

WOB---the pressure of the drill, kN.

In described steps d, create MLCF data track and MLGA data track respectively, and combine MLCF data track and MLGA data track make MLCF ?MLGA X plot.

Its separately data track range establishing method be:

Setting MLCF and MLGA road is M road, road to be placed, corresponding data codomain is (m, n), Ze Tu road range arranges rule can be expressed as (-min (abs (m), abs (n), min (abs (m), abs (n)).

Wherein, min (x, y) is the function differentiating minimum value in x, y,

Abs (x) is ABS function.

In described step e, according to MLCF ?MLGA X plot, MLCF declines and represents stratum brill chance clay mineral (shale) ratio decline, MLCF index rises and then characterizes the raising of corresponding well dark drilling strata clay mineral (shale) ratio, in other words, the friability index of MLCF index and corresponding well deep stratum is inversely proportional to; And the drilling fluid hydrocarbon composition change of MLGA parameter characterization mud logging equipment admission, be directly proportional to the content of organic matter of the dark drilling strata of corresponding well.

Its discriminant approach: the rising of MLCF index (rising of clay mineral content), MLGA index decreased (stratum hydrocarbonaceous amount is few), then sign corresponding well dark drilling strata (hydrocarbonaceous) reservoir is owed and is educated, (clay mineral content reduces MLCF index decreased, brittle mineral content raise), MLGA index rise (stratum hydrocarbonaceous amount increase, the content of organic matter improves), and both have intersection on figure road, then characterize corresponding well dark drilling strata (hydrocarbonaceous) reservoir and comparatively grow.

As shown in Figure 1, in figure, A represents, at the interval that the clay index of instruction reservoir clay content situation is higher, the drilling fluid hydrocarbonaceous volume index characterizing reservoir hydrocarbonaceous feature is also in low value, shows that both variation tendencies are substantially different.In figure, B represents, clay index (MLCF) and the positive correlation of experimental determination clay mineral content, drilling fluid hydrocarbonaceous amount variation index (MLGA) and the positive correlation of experimental determination organic carbon content, the intersection of MLCF and MLGA road significantly then indicates reservoir development.

Embodiment 2

A kind of unconventional gas reservoir reservoir knows method for distinguishing fast, comprises the steps:

1, Data Source: compile zone of interest well logging engineering, geologic parameter (real-time logging data, late logging data)

2, well logging clay index is calculated, i.e. MLCF; And well logging drilling fluid hydrocarbon components variation index, i.e. MLGA;

3, create MLCF data track and MLGA data track respectively, and combine above-mentioned figure road making X plot;

4, MLCF decline represents stratum and bores the decline of chance clay mineral (shale) ratio, if and MLGA parameter rising simultaneously shows that the drilling well liquid hydrocarbon component that mud logging equipment is enrolled rises to some extent, then think that corresponding well depth (adopts real-time well depth for MLCF, and MLGA adopts landwaste to be late well depth) bore and meet reservoir, reservoir development degree and Gas-bearing Characteristics is qualitatively judged, for completion acid fracturing, waterfrac treatment volume increase are constructed and provide foundation with the work of brill well logging RESERVOIR RECOGNITION depending on the two difference degree on X plot.

Below calculating well logging clay index M LCF is described in detail.

Suppose bit wear degree without sudden change in certain depth interval, when boring chance Different Strata, due to subterranean minerals classification and corresponding mineral content difference, drilling efficiency also exists significant difference.

Digging teeth completes the movement in a curve along the borehole wall in drilling process, suppose that hole diameter is stablized, then visual brill tooth movement locus system is along the movement in a curve of cylinder positive camber, as shown in Figure 1, along with strata condition change, brill tooth movement locus change on simulation cylinder positive camber developed surface is obvious, but this track can be approximately straight line in minimum drilling depth scope σ x, and its slope is relevant with brill tooth stress factor.

Suppose that the motion path of edge brill tooth has the Σ F that makes a concerted effort to be making a concerted effort of down-hole multi-acting force, suppose in drill bit drilling process, the Σ F that makes a concerted effort is by the component F only combining driven rotary acting at drilling rod and drill collar ₁with at the force component F done work along well direction ₂synthesis, and if only consider formation factor, then F ₁do work and F ₂the ratio that does work showed the overall efficiency of bit operation to a certain extent, characterize the ratio at the power of longitudinal direction and side direction when the outer sidetracking tooth of drill bit creeps into simultaneously.

As Fig. 3 bit cutting creeps in shown in ideal model, that is,

F ₁＝ΣF·sinθ，

F ₂＝ΣF·cosθ

F ₁power is

$W_1=P_1\·\frac{S_1}{t}$

Circumferencial direction, drilling direction F ₂power can be expressed as

$P_2=F_1\·\frac{S_2}{t}.$

As in the stressed schematic diagram of Fig. 2 drill bit outer rim monodentate,

MLCF＝lg(∫P ₁/P ₂dx)/WOB/dbit·ROP/60

Wherein,

$\begin{array}{c}{P}_1/P_2=\frac{\mathrm{\ΣF}\·\sin \mathrm{\θ}\·2\mathrm{\π}\·\mathrm{dbit}\·\mathrm{RPM}\·\mathrm{\σx}\·\frac{\mathrm{\σx}\·\mathrm{ROP}}{\mathrm{ROP}\·\mathrm{\σx}}}{\mathrm{\ΣF}\·\cos \mathrm{\θ}\·\mathrm{\σx}\·\frac{1}{\mathrm{ROP}\·\mathrm{\σx}}}\\ =0.002\mathrm{\π}\·\mathrm{dbit}\·\mathrm{RPM}\·\mathrm{\σx}\·\mathrm{ROP}\·60\·\mathrm{tg\θ}\\ =(0.002\mathrm{\π}\·\mathrm{dbit}\·\mathrm{RPM}\·\mathrm{\σx}\·\frac{\mathrm{ROP}}{\mathrm{\σx}})\·2\mathrm{\π}\·\mathrm{dbit}\·\mathrm{RPM}\·\mathrm{\σx}\·\mathrm{ROP}\end{array}$

$={\left(0.002\mathrm{\π}\right)}^2\·{\left(\mathrm{dbit}\right)}^2\·{\left(\mathrm{RPM}\right)}^2\·{\left(\mathrm{ROP}\right)}^2\·\mathrm{\σx}$

Namely have,

MLCF=lg[(0.002π) ²·(dbit) ²·(RPM) ²·(60·ROP) ²/WOB/(0.001·dbit)·ROP·60]

Wherein,

MLCF---well logging stratum clay content index;

RPM---drilling speed, r/min;

WOB---the pressure of the drill, kN;

ROP---rate of penetration, h/m;

Dbit---bit diameter, mm.

Use waterpower screw rod because shale gas exploitation is a large amount of, cause the true drilling speed of downhole drill bit to be difficult to measure therefore setting MLCF calculates and singly turns average power ratio at every turn.

That is,

MLCF=lg[(0.002π) ²·(dbit) ²·(60·ROP) ²/WOB/(0.001·dbit)·ROP·60]

Adopt drilling well liquid hydrocarbon component to characterize as reservoir oil-gas possibility is approximate, introduce well logging drilling fluid hydrocarbon components variation index (MLGA) its computing method as follows:

MLGA＝(M-Aver(M))/(60·σM·ROP·WOB)

Wherein: MLGA---well logging drilling fluid hydrocarbon components variation index, is called for short hydrocarbon resistivity index;

M---light hydrocarbon component and heavy hydrocarbon component percentage composition, read value according to chromatogram, dimensionless;

Aver (x)---mean function;

σ M---light hydrocarbon component and heavy hydrocarbon component percentage composition standard deviation;

ROP---during brill, h/m;

WOB---the pressure of the drill, kN.

Embodiment 3

Through-stone oil Logging Industry new opplication method of the present invention, put forth effort high level overview, hold logging parameters and bore and meet reservoir characteristic, be applicable to the unconventional reservoir such as compact sandstone gas, shale gas logging explanation, specifically comprise following flow process:

1, utilize when boring, the well logging engineering parameter such as the pressure of the drill, bit diameter calculates well logging clay index M LCF;

2, methane gas content approximate treatment drilling strata free gas content index M LGA index is utilized;

3, the MLCF index of characterizing formation clay mineral content and the MLGA index intersection of characterizing formation free gas content situation is utilized, formed MLCF ?MLGA intersection can characterize micro-gas-bearing horizon with being beneficial to and preserve, be convenient to the interval transform, can evaluate by the favourable interval relatively given prominence to of the raw hydrocarbon potentiality of formation, raw storage configuration, transformation potentiality.According to MLCF ?MLGA X plot, MLCF declines and represents stratum brill chance clay mineral (shale) ratio decline, MLCF index rises and then characterizes the raising of corresponding well dark drilling strata clay mineral (shale) ratio, in other words, the friability index of MLCF index and corresponding well deep stratum is inversely proportional to; And the drilling fluid hydrocarbon composition change of MLGA parameter characterization mud logging equipment admission, be directly proportional to the content of organic matter of the dark drilling strata of corresponding well.

Its discriminant approach: the rising of MLCF index (rising of clay mineral content), MLGA index decreased (stratum hydrocarbonaceous amount is few), then sign corresponding well dark drilling strata (hydrocarbonaceous) reservoir is owed and is educated, (clay mineral content reduces MLCF index decreased, brittle mineral content raise), MLGA index rise (stratum hydrocarbonaceous amount increase, the content of organic matter improves), and both have intersection on figure road, then characterize corresponding well dark drilling strata (hydrocarbonaceous) reservoir and comparatively grow.

Claims (7)

1. unconventional gas reservoir reservoir knows a method for distinguishing fast, it is characterized in that, comprises the steps:

A, compile zone of interest well logging engineering parameter and geologic parameter;

B, well logging engineering parameter and geologic parameter is utilized to calculate well logging clay index M LCF;

C, well logging engineering parameter and geologic parameter is utilized to calculate drilling strata free gas content index M LGA;

D, utilize the well logging clay index M LCF that calculates and drilling strata free gas content index M LGA, make MLCF ?MLGA X plot;

E, utilize MLCF ?MLGA X plot unconventional gas reservoir reservoir development situation is identified fast.

2. unconventional gas reservoir reservoir according to claim 1 knows method for distinguishing fast, it is characterized in that: in described step a, well logging engineering parameter and geologic parameter comprise the zone of interest of comprehensive logging instrument record with brill drilling fluid performance parameters, in real time logging data, late logging data.

3. unconventional gas reservoir reservoir according to claim 1 and 2 knows method for distinguishing fast, it is characterized in that: in described step b, and MLCF computing method are as follows:

MLCF＝lg[(0.002π) ²·(dbit) ²·(RPM) ²·(60.ROP) ²/WOB/(0.001·dbit)·ROP·60]

Wherein MLCF---well logging stratum clay content index;

RPM---drilling speed, r/min;

WOB---the pressure of the drill, kN;

ROP---rate of penetration, h/m;

Dbit---bit diameter, mm.

4. unconventional gas reservoir reservoir according to claim 3 knows method for distinguishing fast, it is characterized in that: in described step b, reservoir exploitation is used to the situation of waterpower screw rod, because drill bit true drilling speed in shaft bottom is difficult to measure, therefore each brill tooth of setting MLCF calculating outer rim singly turns average power ratio at every turn;

That is,

MLCF＝lg[(0.002π) ²·(dbit) ²·(60.ROP) ²/WOB/(0.001·dbit)·ROP·60]。

5. the unconventional gas reservoir reservoir according to claim 1,2 or 4 knows method for distinguishing fast, it is characterized in that: in described step c, adopt drilling well liquid hydrocarbon component to characterize as reservoir oil-gas possibility is approximate, introduce well logging drilling fluid hydrocarbon components variation index (MLGA) its computing method as follows:

MLGA＝(M-Aver(M))/(60·σM·ROP·WOB)

Wherein: MLGA---well logging drilling fluid hydrocarbon components variation index, is called for short hydrocarbon resistivity index;

M---light hydrocarbon component and heavy hydrocarbon component percentage composition, read value according to chromatogram, dimensionless;

Aver (M)---mean function;

σ M---light hydrocarbon component and heavy hydrocarbon component percentage composition standard deviation;

ROP---during brill, h/m;

WOB---the pressure of the drill, kN.

6. unconventional gas reservoir reservoir according to claim 5 knows method for distinguishing fast, it is characterized in that: in described steps d, create MLCF data track and MLGA data track respectively, its separately data track range establishing method be: setting MLCF and MLGA road be M road, road to be placed, corresponding data codomain is (m, n), Ze Tu road range arranges rule and can be expressed as:

(-min(abs(m),abs(n),min(abs(m),abs(n))

Wherein, min (x, y) is the function differentiating minimum value in x, y, and abs (x) is ABS function;

And combine MLCF data track and MLGA data track make MLCF ?MLGA X plot.

7. according to claim 1, 2, unconventional gas reservoir reservoir described in 4 or 6 knows method for distinguishing fast, it is characterized in that: in described step e, its recognition method is: MLCF index rises (rising of clay mineral content), MLGA index decreased (stratum hydrocarbonaceous amount is few), then sign corresponding well dark drilling strata (hydrocarbonaceous) reservoir is owed and is educated, (clay mineral content reduces MLCF index decreased, brittle mineral content raises), MLGA index rises, and (stratum hydrocarbonaceous amount increases, the content of organic matter improves), and both have intersection on figure road, then characterize corresponding well dark drilling strata (hydrocarbonaceous) reservoir comparatively to grow.