The acquisition methods of shale gas-bearing formation standardization open-flow capacity based on gassiness index
Technical field
Shale gas exploration and development has become world's focus, and the U.S., Canada have carried out shale gas in multiple basins
Commercial-scale operation.Equally, the shale gas stock number very abundant of China's Main Basins and area.Studies have shown that only Sichuan Basin
Shale gas stock number be equivalent to 1.5 times or more of China basin conventional gas stock number.Therefore, China's shale gas resource
Amount is abundant, and fair exploration is wide.
Shale gas exploration and development is world-class technical problem.Currently, it is domestic Shale Gas Accumulation mechanism, resource potential,
Evaluating reservoir etc. achieves huge advance, but the research in terms of shale gas horizontal productivity analysis is still in the starting stage,
It is especially in terms of the acquisition of shale gas horizontal well open-flow capacity to rest on theoretical research stage more.And traditional Absolute Open Flow of Gas Wells
Acquisition methods mainly for lithology be sand shale and carbonate rock, effect that these methods obtain in shale is simultaneously paid no attention to
Think.
Background technique
Open-flow capacity prediction is a highly important link in natural gas exploration and development, is to reservoir quality, reservoir stream
The comprehensive evaluation index of body oil-containing property and its oil productive capacity, while being also one of most important index.
Shale gas refers to that main body is located in dark-coloured mud shale or high-carbon mud shale, is to be primarily present with absorption or free state
The gas accumulation of mode.Shale gas reservoir has the characteristics that ultralow porosity, permeability;And portion gas is adsorbed in reservoir rock
Particle surface is present in reservoir with ADSORPTION STATE, this brings difficulty to shale gas interpretation and evaluation.Shale gas well requires before going into operation
Massive hydraulic fracturing is carried out, more there is the influence factor of its Special complex compared with normal gas pools so as to cause shale gas reservoir production capacity.
Traditional absolute open flow (AOF) acquisition methods are mainly one point method and pseudopressure method etc., are realized by well testing means,
These are all to establish open-flow capacity equation under determining original gas reservoir pressure.For shale gas reservoir, since seepage flow mechanism is complicated,
Applicable open-flow capacity model is difficult to set up by these methods.
Summary of the invention
The purpose of the present invention is statuses in view of the above technology, it is desirable to provide a kind of method is easy, can improve shale gas well without
Choked flow amount precision of prediction, and be able to satisfy scene and survey the shale gas-bearing formation standardization based on gassiness index of logging explanation needs without choked flow
The acquisition methods of amount.
The implementation of the object of the invention is the acquisition side of the shale gas-bearing formation standardization open-flow capacity based on gassiness index
Method, specific steps are as follows:
1) work area is obtained by measuring logging data and has tried shale gas horizontal well horizontal segment shale gas-bearing formation parameter, design parameter is
Gas pay thickness H, horizontal section length L, pressure coefficient Kf, porosity POR, gas saturation Sg and organic carbon content TOC;
2) obtain and tried shale gas horizontal well horizontal segment shale gas-bearing formation fracturing parameter, design parameter be fracturing fluid volume Vf,
Pressure break supporting agent volume Vs;
3) shale gas horizontal well horizontal segment shale gas-bearing formation open-flow capacity AOFg has been tried by the acquisition of tested productivity data;
4) it is successively calculated with the parameter that step 1), step 2) and step 3) obtain and has tried shale gas horizontal well horizontal segment page
Rock gas-bearing formation fracturing reform index IFR, standardization open-flow capacity IAOF, gassiness index Ig, specific formula is as follows:
IFR=(Vf+Vs)/10000,
IAOF=AOFg/L/IFR,
Ig=H × Kf × POR × Sg × TOC;
In formula: fracturing fluid volume Vf dimension is m3,
Pressure break supporting agent volume Vs dimension is m3,
Fracturing reform index IFR dimension is 104m3Or 10km3,
Horizontal section length L dimension is hm or 100m,
Thickness H dimension is m,
Open-flow capacity AOFg dimension is 104m3/ d,
Standardize open-flow capacity IAOFDimension is 104m3/d/hm/104m3,
Thickness H dimension is m,
Pressure coefficient Kf dimensionless,
Porosity POR, gas saturation Sg dimension are decimal,
Organic carbon content TOC dimension is %;
5) by the standardization open-flow capacity I of calculatingAOFThe gassiness index Ig calculated with corresponding well testing passes through least square
Method determines model IAOF=a × eb×IgModel coefficient a, b;
6) work area horizontal well horizontal segment shale gas-bearing formation parameter to be predicted is obtained by measuring logging data, design parameter is gas-bearing formation
Thickness H 1, pressure coefficient Kf 1, porosity POR 1, gas saturation Sg 1 and organic carbon content TOC 1;
7) horizontal well horizontal segment shale gas-bearing formation gassiness index Ig1 to be predicted is calculated with the parameter that step 6) obtains;
8) model I is utilized0OF1=a × eb×Ig1Calculate horizontal well horizontal segment shale gas-bearing formation standardization open-flow capacity to be predicted
IAOF1;
9) shale gas-bearing formation for drawing well to be predicted standardizes open-flow capacity vertical cross section, and it is horizontal to export horizontal well to be predicted
The shale gas-bearing formation open-flow capacity calculated result of section.
The present invention solves traditional open-flow capacity acquisition methods in the shale gas-bearing formation open-flow capacity accuracy of prediction level well
It is not high, poor reliability the problem of, and more easier than traditional open-flow capacity acquisition methods, cost is lower, and scene is more real
With.
The present invention applies 25 mouthfuls of wells in certain shale gas field, and the shale gas-bearing formation that the present invention calculates standardizes open-flow capacity co-occurrence
Standardization open-flow capacity after the open-flow capacity conversion that field pressure break gas testing obtains is close, and mean error is no more than 20%, can reach
The needs of prediction scene standardization open-flow capacity.
Detailed description of the invention
Fig. 1 is workflow block diagram of the present invention,
Fig. 2 is that 10 mouthfuls of F shale of the present invention gas field well standardizes open-flow capacity and gassiness index cross plot,
Fig. 3 is that S3HF well shale gas-bearing formation standardizes open-flow capacity vertical cross section,
Fig. 4 is that S8HF well shale gas-bearing formation standardizes open-flow capacity vertical cross section.
Specific embodiment
Referring to Fig.1, specific steps of the invention are as follows:
1) the shale gas-bearing formation parameter that shale gas horizontal well has been tried in work area is obtained by measuring logging data, design parameter is gas-bearing formation
Thickness H, horizontal section length L, pressure coefficient Kf, porosity POR, gas saturation Sg and organic carbon content TOC;
2) the shale gas-bearing formation fracturing parameter for having tried shale gas horizontal well horizontal segment is obtained, design parameter is fracturing fluid volume
Vf, pressure break supporting agent volume Vs;
3) the open-flow capacity AOFg for having tried shale gas horizontal well horizontal segment is obtained by tested productivity data;
4) page for the shale gas horizontal well horizontal segment tested successively is calculated with the parameter that step 1) and step 2) obtain
Rock gas-bearing formation fracturing reform index IFR, standardization open-flow capacity IAOFWith gassiness index Ig;
5) the shale gas horizontal well horizontal segment shale gas-bearing formation of examination of calculating is standardized into open-flow capacity IAOFIt has been tried with corresponding
The gassiness index Ig that well calculates determines model I by least square methodAOF=a × eb×IgModel coefficient a, b;
6) the shale gas-bearing formation parameter of work area shale gas horizontal well horizontal segment to be predicted is obtained by measuring logging data, specifically
Parameter is gas pay thickness H1, pressure coefficient Kf1, porosity POR1, gas saturation Sg1 and organic carbon content TOC 1;
7) the shale gas-bearing formation gassiness index of shale gas horizontal well horizontal segment to be predicted is calculated with the parameter that step 6) obtains
Ig1;
8) model I is utilizedAOF1=a × eb×Ig1The shale gas-bearing formation for calculating horizontal well horizontal segment to be predicted is standardized without choked flow
Measure IAOF1;
9) shale gas-bearing formation for drawing well to be predicted standardizes open-flow capacity vertical cross section, exports the standardization of well to be predicted
Open-flow capacity calculated result.
The present invention is described in detail with specific embodiment below.
One: F shale gas field S3HF well of example, proving standardization open-flow capacity calculated result.
1) by measuring logging data obtain 10 mouthfuls of F shale gas field tried horizontal well (S1H well, S1-2H well, S1-3HF well,
S6-2HF well, S7-2HF well, S8-2HF well, S9-2HF well, S10-2HF well, S11-2HF well, S12-3HF well) horizontal segment shale
Gas pay thickness H, horizontal section length L, pressure coefficient Kf, porosity POR, gas saturation Sg and the organic carbon content of gas-bearing formation
TOC;
2) 10 mouthfuls are obtained and has tried fracturing fluid volume Vf, pressure break branch used in shale gas horizontal well horizontal segment shale gas-bearing formation pressure break
Hold agent volume Vs;
3) 10 mouthfuls of shale gas-bearing formation open-flow capacities for having tried shale gas horizontal well horizontal segment are obtained by tested productivity data
AOFg;
4) according to step 1), step 2) and step 3) obtain parameter successively calculate 10 mouthfuls well testing gas-bearing formation fracturing reform refer to
Number IFR, standardization open-flow capacity IAOFWith gassiness index Ig;
5) the standardization open-flow capacity I that will be calculated in step 4)AOFIt is true by least square method with the gassiness index Ig calculated
Cover half type IAOF=a × eb×IgModel coefficient a=0.348, b=0.2496 (see Fig. 2);
6) horizontal well S3HF well horizontal segment shale gas-bearing formation parameter is obtained by measuring logging data, S3HF gas well gas layer thickness H 1 is flat
Be 40m, pressure coefficient Kf1 average out to 1.45, porosity POR1 average out to 0.055, gas saturation Sg1 average out to 0.552,
Organic carbon content TOC1 average out to 2.36%;
7) calculating well S3HF well horizontal segment gas-bearing formation gassiness index Ig1 to be predicted by the parameter that step 6) obtains is 4.16;
8) model I is utilizedAOF1=a × eb×Ig1The shale gas-bearing formation for calculating S3HF well horizontal segment standardizes open-flow capacity;
9) calculated result is exported, S3HF well shale gas-bearing formation standardization open-flow capacity vertical cross section (see Fig. 3), S3HF are drawn
The standardization open-flow capacity I that well calculatesAOF1 average out to 0.982 × 104m3/d/hm/104m3.The complete well pressure break gas testing of S3HF well obtains
Shale gas-bearing formation open-flow capacity is 40.01 × 104m3/ d, extended horizontal depth 13.98hm (1398m), fracturing fluid used and supporting agent are total
Volume is 2.96 × 104m3, being converted into shale gas-bearing formation standardization open-flow capacity is 0.967 × 104m3/d/hm/104m3, error is
1.6%, less than 20%, meet the shale gas-bearing formation open-flow capacity prediction needs that logging explanation work is surveyed at scene.
Two: F shale gas field S8HF well of example, verifying predict shale gas horizontal well using shale gas-bearing formation standardization open-flow capacity
Open-flow capacity calculates error.
1) S8HF well is a bite shale gas prospect pit of F shale gas field, can continue to use model I in example oneAOF=a × eb×IBe
Number a=0.348, b=0.2496;
2) S8HF well shale gas-bearing formation parameter, S8HF well well section 2781-2825m shale gas thickness are obtained by measuring logging data
Degree H is 44m, pressure coefficient Kf is 1.45, passes through porosity POR, gas saturation Sg, organic carbon by depth interval of 0.125m
Content TOC calculates gassiness index Ig, then calculates shale gas-bearing formation by gassiness index Ig and standardize open-flow capacity IAOF, draw continuous
Shale gas-bearing formation standardize open-flow capacity vertical cross section (see Fig. 4);
3) it calculates S8HF well 2781-2825m well section shale gas-bearing formation and standardizes open-flow capacity average out to 0.71 × 104m3/d/
hm/104m3。
4) calculated result is exported, S8HF well 2781-2825m gas-bearing formation standardizes open-flow capacity average out to 0.71 × 104m3/d/
hm/104m3, sidetrack horizontal well horizontal segment shale gas-bearing formation length is 15.07hm (1507m), and fracturing work is using fracturing fluid and supports
Agent total volume is 4.0 × 104m3, the open-flow capacity parameter prediction sidetrack horizontal well horizontal segment shale is standardized using shale gas-bearing formation
Gas-bearing formation open-flow capacity is 0.71 × 15.07 × 4.0=42.8 (104m3/ d), the gas well gas layer sidetrack horizontal well horizontal segment production test
Obtain 48.5 × 104m3/ d open-flow capacity, prediction error is 11.8%, less than 20.0%, meets the page that logging explanation work is surveyed at scene
The prediction of rock gas-bearing formation open-flow capacity needs.