CN104965237A - Method of quantitatively and optimally selecting unconventional oil-gas favorable area - Google Patents

Abstract

A method of quantitatively and optimally selecting a unconventional oil-gas favorable area is disclosed. According to planar isoline distribution of different geological parameters, numeralization is performed through software. According to promotion and obstruction effects of the different geological parameters on the unconventional oil-gas favorable development area, a positive correlation parameter and a negative correlation parameter are divided and developed favorable degree calculations are performed respectively. According to an unconventional oil-gas exploration practice and a reality of a research area development geology condition, assignment is performed on weight of each geological parameter respectively and calculation is performed so that a size of unconventional oil-gas development favorability of different planar position target layer segments is obtained. According to an unconventional oil-gas favorable development coefficient of different planar positions, a preferable favorable development area is compared and analyzed. Through quantitatively and optimally selecting the unconventional oil-gas favorable development area, an exploration target area can be visually, rapidly and optimally selected. Important geological information and basis are provided for unconventional oil-gas exploration and development.

Description

A kind of method of quantitatively preferred unconventionaloil pool Favorable Areas

Technical field

The present invention relates to oil and gas exploitation technical field, particularly in the unconventionaloil pool field such as coal-seam gas, shale oil gas, tight sand oil gas a kind of quantitatively preferably oil gas grow the method for Favorable Areas.

Background technology

Unconventionaloil pool has the features such as the wide and unit area abundance of distribution area is low usually, generally comprises densification and hyper-tight sandstone oil gas, shale oil gas, overweight (thick) oil, bituminous sandstone, coal-seam gas, Water Soluble Gas.At present, the Favorable Areas method for optimizing of coal-seam gas, shale oil gas or tight sand oil gas adopts multifactor method of superposition or geology method of identification usually, and multifactor method of superposition is usually carried out plane isopleth according to indexs such as organic geochemistry (TOC, Ro), reservoir physical (factor of porosity, permeability), structure buried depths and superposed preferred Favorable Areas; And geology method of identification Main Basis seismic inversion, logging response character come preferred favourable interval or area; Above method, can not the Favorable Areas of optimizing evaluation unconventionaloil pool quantitatively mainly through the preferred Favorable Areas of method qualitatively, can not the profitable probability size of comparative analysis different regions oil-gas formation.

Summary of the invention

Can not the deficiency of quantitative evaluation and preferred unconventionaloil pool Favorable Areas in order to overcome multifactor method of superposition or geology method of identification, the object of the present invention is to provide a kind of method of quantitatively preferred unconventionaloil pool Favorable Areas; The method is based upon on the basis of single factor test quantitative test, by carrying out weight analysis to differently quality factor, according to exploration practices and actual geological condition, the importance degree of comparative analysis differently quality factor is weighted summation, thus the unconventionaloil pool calculating this area grows profitable size, the present invention not only preferred unconventionaloil pool Favorable Areas of growing quantitatively, can also contrast the superiority-inferiority of different regions unconventionaloil pool formation condition.

In order to achieve the above object, technical scheme of the present invention is:

A method for quantitatively preferred unconventionaloil pool Favorable Areas, comprises the following steps:

Step one, first different to study area geologic parameters carry out mathematical standard, number of planes value is carried out in plane isopleth distribution according to each geologic parameter, and described geologic parameter comprises organic carbon content, evolution level, objective interval thickness, structure buried depth, factor of porosity, permeability;

Facilitation is played in the growth of geologic parameter to unconventionaloil pool of the organic carbon content in step 2, geologic parameter, objective interval thickness, factor of porosity and preservation oil gas, be called positively related parameter, otherwise be negative correlation geologic parameter, the mathematical standard formula of positive correlation geologic parameter and negative correlation geologic parameter is respectively with wherein P _xfor single factor test geological criteria parameter value, X is parameter value, X _minfor minimum value, X _maxfor maximal value;

It is P=a that step 3, unconventionaloil pool grow favourable coefficient formulas ₁p ₁+ a ₂p ₂+ ... + a _ip _i+ ... + a _np _n+ k, wherein P is for growing favourable coefficient, 0≤P≤1; a _irepresent the weight of i-th parameter; P _irepresent the normalizing parameter value of i-th parameter; K is correction factor, according to actual exploration practices and research experience value; N represents the number of parameters participating in calculating;

The favourable factor v of the growth that step 4, step 3 calculate is larger, illustrates that the possibility of this area's growth unconventionaloil pool is larger, thus the development area of preferred unconventionaloil pool; According to the favourable coefficient value of growth of diverse location, drafting pattern, and compare the profitable size of different regions growth unconventionaloil pool.

Beneficial effect: the principle that the present invention quantizes owing to adopting geologic agent, has constituency simple to operate, quantifiable feature.Grow profitable quantification and drafting pattern by objective interval unconventionaloil pool in different regions in study area, can contrast comparatively intuitively and preferably grow Favorable Areas, solve the drawback that qualitative evaluation in the past has multi-solution.

Accompanying drawing explanation

Fig. 1 is that quantitatively preferably unconventionaloil pool grows Favorable Areas process flow diagram.

Fig. 2 A is WEST DEPRESSION OF LIAOHE OILFIELD organic carbon content TOC flat distribution map; Fig. 2 B thermal evolution of organic matter Ro flat distribution map; Fig. 2 C objective interval thickness distribution figure; Fig. 2 D grows favourable index layer distribution plan.

Embodiment

Below in conjunction with the drawings and specific embodiments, the present invention is described in detail.

Embodiment explanation is carried out according to WEST DEPRESSION OF LIAOHE OILFIELD s_4 formation unconventionaloil pool (shale oil gas).Combined with file degree, exploration practices and growth geologic condition, choose these three geologic parameters of objective interval thickness (H), organic carbon content (TOC) and thermal evolution of organic matter (Ro) grow Favorable Areas principal element as quantitatively preferred unconventionaloil pool.

Step one, the rich organic shale thickness flat distribution map (Fig. 2 A) of drafting study area s_4 formation, organic carbon content flat distribution map (Fig. 2 B) and thermal evolution of organic matter flat distribution map (Fig. 2 C), afterwards, grid number value is carried out according to distribution of contours, precision of suing for peace as required is divided into the grid (as 1000*1000 etc.) of different densities, makes different grid have different parameter values.

Step 2, known by theoretical research, in research, rich organic shale thickness, organic carbon content and the growth of thermal evolution of organic matter to unconventionaloil pool have positive correlation.Therefore, each geologic parameter value is pressed mathematical standard formula carries out standard parameter, makes standard parameter value between 0-1; If Du126Jing place objective interval TOC is 2%, study area maximal value is 5.5%, and minimum value is 0.5%, then the TOC standardized value at this place is P _{du 126}=(2%-0.5%)/(5.5%-0.5%)=0.3, other each points all carry out standard on data by this formula.In like manner, thickness and evolution level also carry out standard on data by this flow process.

Step 3, foundation study area exploration practices and actual geologic condition, the weight of above-mentioned each geologic parameter is assigned 0.4,0.3 and 0.4 respectively.Therefore this area's unconventionaloil pool (shale oil gas) grows profitable coefficient probability P=0.4P _tOC+ 0.3P _ro+ 0.4P _h.Grow favourable coefficient larger, shale oil gas developmentally matter condition is better.As shut out, 126 well TOC standardized values are 0.3, Ro standardized value is 0.2, the standardized value of H is 0.5, getting K value is 0, then unconventionaloil pool grows profitable FACTOR P=0.4*0.3+0.3*0.2+0.4*0.5=0.38, this is the profitable coefficient that this place's unconventionaloil pool is grown, and grows the size of unconventionaloil pool potentialities of development for characterizing this place.

Step 4, by carrying out mathematical standard to TOC, Ro and shale thickness, and favourable coefficient value being grown to unconventionaloil pool calculate and drafting pattern (Fig. 2 D).As we know from the figure, study area unconventionaloil pool is grown favourable coefficient and is substantially all greater than 0.2, place, Shuguang area higher with the favourable coefficient of oil-gas accumulation in promotion-Lei family area, can reach more than 0.6, the geologic condition showing the unconventional growth of this area is superior, and the probability of Enrichment And Reservoiring is larger; The favourable coefficient of growth near two 202 wells in Niuxintuo Region and south in addition also reaches more than 0.4, has good unconventionaloil pool (shale oil gas) equally and grows geologic condition.And, can comparative study district diverse location or the different study areas unconventionaloil pool profitable size of growing by growing favourable coefficient value and distribution thereof.

Grow Favorable Areas and actual exploration situation by quantitatively preferred unconventionaloil pool and adopt the preferred Favorable Areas of multifactor overlay technique substantially identical, showing good accuracy and practicality.

Claims (1)

1. a method for quantitatively preferred unconventionaloil pool Favorable Areas, is characterized in that, comprise the following steps:

Step one, first different to study area geologic parameters carry out mathematical standard, number of planes value is carried out in plane isopleth distribution according to each geologic parameter, and described geologic parameter comprises organic carbon content, evolution level, objective interval thickness, structure buried depth, factor of porosity, permeability;

Facilitation is played in the growth of geologic parameter to unconventionaloil pool that organic carbon content in step 2, geologic parameter, objective interval thickness, factor of porosity are conducive to raw hydrocarbon, storage hydrocarbon and preservation oil gas, be called positively related parameter, otherwise be negative correlation geologic parameter, the mathematical standard formula of positive correlation geologic parameter and negative correlation geologic parameter is respectively with wherein P _xfor single factor test geological criteria parameter value, X is parameter value, X _minfor minimum value, X _maxfor maximal value;

It is P=a that step 3, unconventionaloil pool grow favourable coefficient formulas ₁p ₁+ a ₂p ₂+ ... + a _ip _i+ ... + a _np _n+ k, wherein P is for growing favourable coefficient, 0≤P≤1; a _irepresent the weight of i-th parameter; P _irepresent the normalizing parameter value of i-th parameter; K is correction factor, according to actual exploration practices and research experience value; N represents the number of parameters participating in calculating;

The favourable factor v of the growth that step 4, step 3 calculate is larger, illustrates that the possibility of this area's growth unconventionaloil pool is larger, thus the development area of preferred unconventionaloil pool; According to the favourable coefficient value of growth of diverse location, drafting pattern, and compare the profitable size of different regions growth unconventionaloil pool.