CN104850742A - Method for calculating CO2 salty water layer mineral sequestration potential - Google Patents

Abstract

The invention belongs to the technical field of geochemistry, in particular to a method for quantitatively calculating a CO2 salty water layer mineral sequestration potential by using a water-rock-CO2 geochemistry reaction. The CO2 sequestration potential is calculated according to the CO2 quantity consumed in the dissolving process of feldspar-like minerals in rock volume per unit and rock effective volume, contribution of calcite dissolving to the CO2 sequestration quantity is not contained in the calculating process, and only the quantity of CO2 consumed in the geochemistry reaction of the feldspar-like minerals is considered.

Description

A kind of calculating CO 2salt water layer mineral seal the method for potentiality up for safekeeping

Technical field

The invention belongs to geochemical techniques field, be specifically related to one and utilize water-rock-CO ₂geochemical reaction quantitatively calculates CO ₂salt water layer mineral seal the method for potentiality up for safekeeping.

Background technology

Under the general layout and background of global climate and environmental pollution, energy-saving and emission-reduction are industries that current government organs actively push forward.CO ₂salt water layer is sealed up for safekeeping and is considered to reduce CO ₂one of most effective method of discharge capacity, existing commercial scale and pilot scale yardstick CO ₂seal test up for safekeeping and also prove that it is feasible technically.A large amount of CO ₂after being injected into salt water layer, can catch with structure and structure, residual gas is caught, and dissolving is caught the mode of catching with mineral and sealed up for safekeeping; From catching form, be then with free state, solubilised state and mineral state form are sealed up for safekeeping.In other words, total CO ₂it is by free state that salt water layer seals potentiality up for safekeeping, solubilised state and mineral state CO ₂three part compositions.Accurate calculating CO ₂salt water layer seals potentiality up for safekeeping for carrying out commercial size profit pilot scale yardstick CO ₂injection project is significant, is one of key factor of addressing.

Current existing CO ₂it is all for free state and solubilised state CO that salt water layer seals potentiality method up for safekeeping ₂seal up for safekeeping gauge calculate, such as carbon sequestration leader forum and american energy office etc. propose catch for structure and structure, residual gas is caught and CO is caught in dissolving ₂seal free state and the solubilised state CO of potentiality computing method and some scholars proposition up for safekeeping ₂seal potentiality computing method up for safekeeping.For mineral state CO ₂seal potentiality up for safekeeping, some scholars adopts the CO on actual geology model-based plinth ₂migration reaction numerical simulation calculates, but inherently there is a lot of uncertainty in numerical model, there is error even mistake in the inaccurate result of calculation that also can cause of the assignment of parameter, and this geochemical model all cannot correct in most cases, and the confidence level providing result is worth discussion.There are some researches show, on-Wan annual time scale in thousand, mineral are sealed up for safekeeping CO ₂the contribution proportion sealing potentiality up for safekeeping is 5%-40%, and the actual amount of sealing up for safekeeping depends on salt water layer formation water geochemistry and Reservoir Minerals component.Structure compared and structure are sealed up for safekeeping and residual gas seals (free state) up for safekeeping and dissolving is sealed up for safekeeping (solubilised state), and the security that mineral are sealed up for safekeeping (mineral state) is best, so need to propose a kind of calculating CO ₂mineral seal the computing method of potentiality up for safekeeping.

In fact, a large amount of CO ₂can local water be dissolved in after being injected into salt water layer, and promote water rock chemical reaction, namely cause a series of geochemical reaction.These courses of reaction can consume a certain amount of CO ₂, generate new secondary mineral, reach the object that mineral are sealed up for safekeeping.So this method is for CO main in current world wide ₂rock type-the sandstone reservoir of reservoir and typical mineral component characteristics thereof, according to these mineral and CO ₂chemical equation interactional with local water, sets up CO in unit rock volume ₂consumption, obtain total mineral and seal potentiality up for safekeeping, for carrying out CO ₂the site addressing that injection test or scale are sealed up for safekeeping and later stage planning provide reference frame.

Summary of the invention

Technical matters to be solved by this invention calculates CO exactly ₂salt water layer mineral seal potentiality up for safekeeping, promote CO ₂the research and development that salt water layer is sealed up for safekeeping.

The present invention proposes a kind of CO based on sandstone reservoir geochemical reaction ₂salt water layer mineral seal potentiality computing method up for safekeeping, can determine CO efficiently and accurately ₂salt water layer mineral seal potentiality up for safekeeping.According to existing research, CO main at present ₂reservoir is sandstone reservoir, and its typical mineral component is potassium feldspar, soda feldspar and lime feldspar and a small amount of carbonate mineral.CO ₂after being injected into salt water layer reservoir, the dissolving of feldspar and carbonate mineral can be promoted.So the ultimate principle of this method is according to the used up CO of feldspathoid course of dissolution in unit rock volume ₂amount and total rock active volume, set up mineral state CO ₂seal potentiality computing method up for safekeeping, obtain CO ₂mineral seal potentiality up for safekeeping.

Sandstone reservoir typical case geochemical reaction: sandstone belongs to petroclastic rock, and comprise chip and cementing matter two parts, chip content is greater than 50% usually.The mineral of sandstone reservoir are primarily of quartz, and feldspar and clay mineral form, and its andesine is mainly potassium feldspar, soda feldspar and lime feldspar; The components such as cementing matter comprises calcareous, siliceous and shale, wherein calcareous cement is based on carbonate mineral.A large amount of CO ₂after being injected into sandstone reservoir, can there is following geochemical reaction (2-1 ~ 2-5) in carbonate mineral and feldspathoid.

2KAlSi ₃o ₈(potassium feldspar)+CO ₂+ 2H ₂o → Al ₂(Si ₂o ₅) (OH) ₄(smalite)+4SiO ₂+ K ₂cO ₃2-2

2NaAlSi ₃o ₈(soda feldspar)+2CO ₂+ 3H ₂o → Al ₂(Si ₂o ₅) (OH) ₄(smalite)+4SiO ₂+ 2NaHCO ₃2-3

NaAlSi ₃o ₈(soda feldspar)+CO ₂+ H ₂o → NaAlCO ₃(OH) ₂(dawsonite)+3SiO ₂2-4

CaAl ₂si ₂o ₈(lime feldspar)+CO ₂+ 2H ₂o → Al ₂(Si ₂o ₅) (OH) ₄(smalite)+CaCO ₃2-5

Because kalzit belongs to least stable mineral, so it is to CO ₂the mineral amount of sealing up for safekeeping produced belongs to temporary and seals up for safekeeping; On the contrary, the course of dissolution of feldspathoid is to CO ₂consumption be permanent sealing up for safekeeping.So, at calculating CO ₂salt water layer mineral are sealed up for safekeeping in potentiality and are not comprised Calcite Dissolution to CO ₂the contribution of the amount of sealing up for safekeeping, only considers that feldspathoid geochemical reaction consumes CO ₂amount.

CO ₂salt water layer mineral seal potentiality computing method up for safekeeping: according to chemical equation 2-2 ~ 2-5, and the dissolving of every 1mol potassium feldspar can consume the CO of 0.5mol ₂, the dissolving of every 1mol soda feldspar can consume the CO of 1mol ₂, the dissolving of every 1mol lime feldspar can consume the CO of 1mol ₂.So, CO ₂salt water layer mineral are sealed potentiality computing method up for safekeeping and can be calculated by through type 2-6, wherein m _cO2cO ₂salt water layer mineral seal total potentiality up for safekeeping, with be that the mineral that the dissolving of potassium feldspar, soda feldspar and lime feldspar produces seal potentiality up for safekeeping respectively, unit is Mt; ρ _k-feldspar, ρ _albiteand ρ _anorthitebe potassium feldspar, soda feldspar and anorthitic density respectively, unit is kg/m ³; V _k-feldspar, V _albiteand V _anothitebe the cumulative volume of potassium feldspar, soda feldspar and lime feldspar mineral respectively, unit is km ³; M _cO2, M _k-feldspar, M _albiteand M _anorthitecO respectively ₂, potassium feldspar, soda feldspar and lime feldspar mineral molal weight, CO ₂molal weight be 44g/mol; A is CO ₂store coefficient of efficiency, dimensionless.

$\begin{array}{c}{m}_{{\mathrm{co}}_{2-K-\mathrm{feldspar}}}=\frac{{\mathrm{\ρ}}_{K-\mathrm{feldspar}}\·V_{K-\mathrm{feldspar}}\·M_{{\mathrm{CO}}_2}\·a}{2\·M_{K-\mathrm{feildspar}}}\\ m_{{\mathrm{co}}_{2-\mathrm{albite}}}=\frac{{\mathrm{\ρ}}_{\mathrm{albite}}\·V_{\mathrm{albite}}\·M_{{\mathrm{CO}}_2}\·a}{M_{\mathrm{albite}}}\\ m_{{\mathrm{co}}_{2-\mathrm{anorthite}}}=\frac{{\mathrm{\ρ}}_{\mathrm{anorthite}}\·V_{\mathrm{anorthite}}\·M_{{\mathrm{CO}}_2}\·a}{M_{\mathrm{anorthite}}}\\ m_{{\mathrm{co}}_2}=m_{{\mathrm{co}}_{2-K-\mathrm{feldspar}}}+m_{{\mathrm{co}}_{2-\mathrm{albite}}}+m_{{\mathrm{co}}_{2-\mathrm{anorthite}}}\end{array}---2-6$

The present invention is based on CO ₂be injected into the geochemical reaction that sandstone salt water layer promotes afterwards, utilize unit rock volume spectra to dissolve used up CO ₂amount and reservoir rock volume, establish CO ₂salt water layer mineral seal potentiality computing method up for safekeeping, can obtain CO exactly ₂salt water layer mineral seal potentiality up for safekeeping.

Embodiment

About CO in reference summary of the invention ₂salt water layer mineral seal potentiality computing method up for safekeeping, based on molecular weight and the data such as density and calculating site sandstone reservoir mineral content of typical spectra, determine the calculating parameter in formula 2-6, can calculate CO ₂salt water layer mineral seal potentiality up for safekeeping.The wherein density p of spectra _k-feldspar, ρ _albiteand ρ _anorthitewith molal weight M _k-feldspar, M _albiteand M _anorthitecan be obtained by inspection information; Spectra cumulative volume V _k-feldspar, V _albiteand V _anorthitecan be determined by the reservoir landwaste of site and various spectra content parameter; Store the value that coefficient of efficiency a can utilize monte carlo method to draw for North America geologic condition with reference to the USDOE extensively adopted in the world at present.Concrete mode is as described below.

The density p of spectra _k-feldspar, ρ _albiteand ρ _anorthite

By By consulting literatures data, potassium feldspar, soda feldspar and anorthitic density are ρ respectively _k-feldspar=2.55-2.67 × 10 ³kg/m ³, ρ _albite=2.55-2.60 × 10 ³kg/m ³and ρ _anorthite=2.75-2.76 × 10 ³kg/m ³.

the molal weight M of spectra _k-feldspar, M _albiteand M _anorthite

Potassium feldspar, soda feldspar and anorthitic molal weight are M respectively _k-feldspar=279.07g/mol, M _albite=262.96g/mol profit M _albite=278.94g/mol.

The volume V of spectra _k-feldspar, V _albiteand V _anorthite

Potassium feldspar, soda feldspar and anorthitic concrete account form are such as formula shown in 2-7.Wherein φ is the average pore of sandstone reservoir, dimensionless; V is the volume of sandstone reservoir, and can be obtained by geologic examination and well-log information, unit is km ³; C _debristhe content ratio of chip in sandstone reservoir, dimensionless; C _feldsparthe content ratio of chip andesine mineral, dimensionless; X _k-feldsapr, X _albiteand X _anorthitebe potassium feldspar, soda feldspar and the lime feldspar content ratio at spectra respectively, dimensionless, these parameters can be analyzed by the mineral constituent of actual sandstone reservoir and obtain measured value.

V _K-feldspar＝V·(1-φ)·C _debris·C _feldspar·X _K-feldspar

V _albite＝V·(1-φ)·C _debris·C _feldspar·X _albite2-7

V _anorthite＝V·(1-φ)·C _debris·C _feldspar·X _anorthite

CO ₂store coefficient of efficiency a

CO ₂store coefficient of efficiency a to control by the dissolution precipitation dynamic process of the nonuniformity of reservoir and anisotropy, mineral and local water contact area and mineral.Widely use at present the parameter value that USDOE obtains according to the Monte Carlo simulation that North America geologic condition carries out in the world, namely 15%, 50% and 85% confidence level condition under, store coefficient of efficiency and be respectively 1%, 2.4% and 4%.

First embodiment

Utilize above-mentioned CO ₂salt water layer mineral seal potentiality computing method up for safekeeping, carried out mineral seal potentiality calculating up for safekeeping to upper Cretaceous series Qingshankou group to the Nenjiang group salt water layer reservoir of the Baokang sedimentary system growth of central depression, Jilin Oil Field south Changling Sag.Reservoir lithology feature shows to be suitable for CO ₂the salt water layer sealed up for safekeeping is Qingshankou group one section, two sections, three sections and Yao Jia group one section, and corresponding cap rock is the thick-layer shape mud stone of Nenjiang group and Yao Jia group two sections and three sections.Qingshankou group one section, two sections, three sections are respectively 430km with Yao Jia group one section of sandstone cumulative volume V ³, 980km ³, 1500km ³profit 80kmn ³; Average pore φ is respectively 14.1%, 18.7%, 18.7% and 9.2%, i.e. CO ₂sealing the total active volume of sand body up for safekeeping is 2459.2km ³.According to the microscopic of actual reservoir core sample, this sandstone, based on landwaste arkosic arenite and feldspar rock-fragment sandstone, forms primarily of quartz, feldspar, landwaste and a small amount of heavy mineral.Chip content is 40 ~ 85%, and chip andesine content is 15 ~ 52%, and in spectra, potassium feldspar, the anorthitic content of soda feldspar profit are respectively 5 ~ 10%, 50 ~ 70% and 20 ~ 35%.Store coefficient of efficiency and be assumed to be 1%.Result shows, based on the CO that the present invention proposes ₂salt water layer mineral seal potentiality computing method up for safekeeping, draw Baokang sedimentary system CO ₂salt water layer mineral are sealed potentiality minimum value profit maximal value up for safekeeping and are respectively 457.5Mt and 5114.4Mt, and wherein soda feldspar and lime feldspar dissolve the CO produced ₂the mineral amount of sealing up for safekeeping is the main contributions that mineral are sealed up for safekeeping, and account for respectively and always seal 60% and 30% of potentiality up for safekeeping, this is relevant with the content characteristics of this area spectra.

Claims (5)

1. one kind calculates CO ₂salt water layer mineral seal the method for potentiality up for safekeeping, it is characterized in that: according to the used up CO of feldspathoid course of dissolution in unit rock volume ₂amount and rock active volume, calculate CO ₂seal potentiality up for safekeeping, in computation process, do not comprise Calcite Dissolution to CO ₂the contribution of the amount of sealing up for safekeeping, only considers that feldspathoid geochemical reaction consumes CO ₂amount.

2. calculate CO as claimed in claim 1 ₂salt water layer mineral seal the method for potentiality up for safekeeping, wherein CO ₂salt water layer mineral seal potentiality up for safekeeping by following formulae discovery:

$m_{{\mathrm{co}}_{2-K-\mathrm{feldspar}}}=\frac{{\mathrm{\ρ}}_{K-\mathrm{feldspar}}\·V_{K-\mathrm{feldspar}}\·M_{{\mathrm{CO}}_2}\·a}{2\·M_{K-\mathrm{feildspar}}}$

$m_{{\mathrm{co}}_2-\mathrm{albite}}=\frac{{\mathrm{\ρ}}_{\mathrm{albite}}\·V_{\mathrm{albite}}\·M_{{\mathrm{CO}}_2}\·a}{M_{\mathrm{albite}}}$

$m_{{\mathrm{co}}_2-\mathrm{anorthite}}=\frac{{\mathrm{\ρ}}_{\mathrm{anorthite}}\·V_{\mathrm{anorthite}}\·M_{{\mathrm{CO}}_2}\·a}{M_{\mathrm{anorthite}}}$

$m_{{\mathrm{co}}_2}=m_{{\mathrm{co}}_2-K-\mathrm{felddpar}}+m_{{\mathrm{co}}_2-\mathrm{albite}}+m_{{\mathrm{co}}_2-\mathrm{anorthite}}$

Wherein M _cO2cO ₂salt water layer mineral seal total potentiality up for safekeeping, with be that the mineral that the dissolving of potassium feldspar, soda feldspar and lime feldspar produces seal potentiality up for safekeeping respectively, unit is Mt; ρ _k-feldspar, ρ _albiteand ρ _anorthitebe potassium feldspar, soda feldspar and anorthitic density respectively, unit is kg/m ³; V _k-feldspar, V _albiteand V _anorthitebe the cumulative volume of potassium feldspar, soda feldspar and lime feldspar mineral respectively, unit is km ³; M _cO2, M _k-feldspar, M _albiteand M _anorthitecO respectively ₂, potassium feldspar, soda feldspar and lime feldspar mineral molal weight, CO ₂molal weight be 44g/mol; A is CO ₂store coefficient of efficiency, dimensionless.

3. calculate CO as claimed in claim 2 ₂salt water layer mineral seal the method for potentiality up for safekeeping, wherein the density p of spectra _k-feldspar, ρ _albiteand ρ _anorthitewith molal weight M _k-feldspar, M _albiteand M _anorthiteobtained by inspection information; Spectra cumulative volume V _k-feldspar, V _albiteand V _anorthitedetermined by the reservoir landwaste of site and various spectra content parameter; CO ₂store the value that coefficient of efficiency a adopts USDOE to utilize monte carlo method to draw for North America geologic condition.

4. calculate CO as claimed in claim 3 ₂salt water layer mineral seal the method for potentiality up for safekeeping, spectra cumulative volume V _k-feldspar, V _albiteand V _anorthitespecific formula for calculation as follows:

V _K-feldspar＝V·(1-φ)·C _debris·C _feldspar·X _K-feldspar

V _albite＝V·(1-φ)·C _debris·C _feldspar·X _albite

V _anorthite＝V·(1-φ)·C _debris·C _feldspar·X _anorthite

Wherein φ is the average pore of sandstone reservoir, dimensionless; V is the volume of sandstone reservoir, and can be obtained by geologic examination and well-log information, unit is km ³; C _debristhe content ratio of chip in sandstone reservoir, dimensionless; C _feldsparthe content ratio of chip andesine mineral, dimensionless; X _k-feldsapr, X _albiteand X _anorthitebe potassium feldspar, soda feldspar and the lime feldspar content ratio at spectra respectively, dimensionless, these parameters can be analyzed by the mineral constituent of actual sandstone reservoir and obtain measured value.

5. calculate CO as claimed in claim 4 ₂salt water layer mineral seal the method for potentiality up for safekeeping, CO ₂store the parameter value that coefficient of efficiency a uses USDOE to obtain according to the Monte Carlo simulation that North America geologic condition carries out, namely 15%, 50% and 85% confidence level condition under, store coefficient of efficiency and be respectively 1%, 2.4% and 4%.