CN1049719C - Method for testing water-covering oil layer saturation degree by using normal boring sample-test reference - Google Patents

Abstract

The present invention relates to a method for measuring the water-flooding oil layer saturation by ordinary boring test data, which belongs to the technical field of oil pool development engineering. The method is used for directly measuring the saturation of a water-flooding oil layer in an oil pool which is exploited in a water injection mode. The method is characterized in that tracers which do not interfere mutually are added into injected water of a water-injecting well and coal water slurry for boring; sampling is carried out through the methods of boring, formation testing, etc., and the various parameters of core samples, fluid samples, etc. are measured; the parameters are substituted into an equation set which is derived from a volume-based model volume model of a pore fluid of the core samples and a volume model of formation testing fluid samples. The method has the advantages of simple boring technology, low cost, improvement of boring labour conditions, wide range of application, easy construction, etc.

Description

Ask the method for waterflooded reservoir saturation ratio with common coring-test data

The invention belongs to the reservoir engineering technical field, be used in the saturation ratio of directly asking waterflooded reservoir in the oil reservoir of water flooding recovery.

Wait " residual oil saturation is determined method " (September nineteen eighty-two of writing [U.S.] D.C. Bond, petroleum industry publishing house publishes) " petroleum gas reserves computational methods " (April nineteen ninety of writing such as in the book the 14th～29 page and 38～41 pages and Yang Tongyou, the publication of petroleum industry publishing house) the 65th～68 page of introduction in the book, the existing method of directly obtaining oil reservoir oil, water saturation is by boring oil-base mud core hole or sealed coring well, or adopt rubber case to core, or pressure core, and analyze oil-containing, the water saturation of its rock core.The advantage of preceding two kinds of methods is more directly to obtain the saturation ratio data of oil reservoir, its weak point is the cost height, complex process, the condition of labor of coring is poor, and gained saturation ratio data only is reliably in pure oil section, to the oil reservoir (as waterflooded reservoir) that has Free water to exist, in the process of coring, because of pressure, variations in temperature, caused in the rock core loss of volatilizing simultaneously of oil, water, so oil-base mud is cored and the resulting saturation ratio data of sealing core drilling equally also is insecure.For sealing core drilling, if rock core is airtight bad, resulting saturation ratio data reliability is poorer.Rubber case is cored and is helped to improve the core recovery of the hard formation of growing very much in soft formation, unconsolidated formation, layer of gravel and crack, has shortened the time of contact of rock core and mud slurry stream in the process of coring.But F to wash away influence still be unavoidable, and in the process of coring, also more complicated is operated in the influence of oil, water volatilization loss in addition in the rock core that can be subjected to equally to produce because of pressure, variations in temperature.Pressure core can seal the rock core of taking from oil reservoir and wherein contained fluid, makes that fluid remains unchanged in the rock core, but it can not prevent the influence of washing away of F, and therefore, the reliability of the saturation ratio data that is obtained also has certain problem.In addition, its coring equipment, centering technique, rock core processing method, also than general coring method complexity many.A kind of technology in addition is to add tracer in core drilling liquid, measures the drilling fluid tracer concentration in core drilling liquid and the rock core simultaneously, determines the filtrate immersion amount in the core sample, to judge the dip-dye degree of F to rock sample.The advantage of this method is that the drilling and coring delivery cost is lower, technology simple, the condition of labor of coring has had improvement.Its weak point is to use limitation of scope, generally only is applicable to the net pay zone of poor permeability.For good penetrability, there is mud seriously to contaminate, oil reservoir (as waterflooded reservoir) the saturation ratio data that it obtained that particularly contains Free water is also unreliable.

The method that the purpose of this invention is to provide a kind of definite oil reservoir saturation ratio, particularly determine the method for waterflooded reservoir saturation ratio, this method has overcome the deficiencies in the prior art, both simplified centering technique, reduced cost, improve the condition of labor of coring, can accurately and directly obtain waterflooded reservoir intensity value and shunt volume again.Have alternative oil-base mud and core or sealing core drilling, have wide range of applications advantages such as easy construction.

The objective of the invention is to realize by following four kinds of schemes.Before the offshoot program explanation, should be noted that: foregoing technical field that the present invention belongs to, useful background technology is understood, retrieves, is examined in invention, the file of the background technology of quoting as proof, the beneficial effect that is had is compared in the purpose of invention and invention with background technology explanation, all be applicable to each offshoot program of the present invention,, in the offshoot program explanation, no longer repeat to give unnecessary details below in order to save the explanation book.

First kind of scheme: ask the waterflooded reservoir saturation ratio with common coring-test data

Injection water at the waterflooded reservoir water injection well adds a kind of tracer, in the mud of usefulness of coring, add another kind of tracer, tracer in the mud must not disturb each other mutually with the tracer that injects water, and to the sampling of the mud of the usefulness of coring, to the oil reservoir boring sample, with the reservoir fluid sampling of formation tester to the rock core section, measure the mud tracer concentration in the F, measure the voids volume of core sample, remaining oil mass volume in the core sample, the water tracer quality is injected on the stratum that contains in the core sample, the mud tracer quality that contains in the core sample, the oil of core sample, the water phase permeability curve, the mixing water yield volume of the reservoir fluid sample that the mensuration formation tester is obtained, the water tracer quality is injected on the stratum that contains in the mixing water, the mud tracer quality that contains in the mixing water, oil volume factor (also can by high pressure physical property sample device sampling and measuring), the underground viscosity of crude oil, the underground viscosity of water is oil, the water phase permeability curve is converted to oil, water phase permeability ratio-water saturation relation curve.

According to the mud tracer concentration in the F of measuring by mud sample, voids volume by core sample mensuration, remaining oil mass volume, the water tracer quality is injected on the stratum, mud tracer quality, oil, the water phase permeability curve, mixing water yield volume by formation testing fluid sample mensuration, the water tracer quality is injected on the stratum that contains in the mixing water, the mud tracer quality that contains in the mixing water, oil volume factor (also can by high pressure physical property sample device sampling and measuring), the underground viscosity of underground viscosity of crude oil and water, the water saturation expression formula derived by the volume-based model of the pore-fluid volume-based model of core sample and formation testing fluid sample of substitution respectively, stratum water yield volume expression formula in the core sample, remaining stratum water yield volume expression formula in the core sample, core sample volatilizees in the process of coring in the equation group of the stratum water yield volume expression formula of loss and shunt volume expression formula, with oil, water phase permeability ratio-water saturation relation curve combination goes out water saturation numerical value and shunt volume by solution by iterative method.In such scheme, when producing well obtains to have contained certain sensitive tracer concentration in the waterflooded reservoir formation water in advance, then needn't add tracer again at the injection water of water injection well, only in the mud of usefulness of coring, add a kind of tracer that does not interfere with each other to each other with waterflooded reservoir formation water tracer, and remaining scheme step is as described in the former scheme, does not repeat them here.

Below in conjunction with the embodiment of accompanying drawing to asking the method for waterflooded reservoir saturation ratio to be described further with common coring-test data.

Fig. 1 is a method site operation schematic diagram of asking the waterflooded reservoir saturation ratio with common coring-test data.

Fig. 2 is the pore-fluid volume-based model of core sample.

Fig. 3 is the volume-based model of formation testing fluid sample.

Fig. 4 is the oil from core sample, the oil that the water phase permeability curve converts to, the relation curve schematic diagram of water phase permeability ratio-water saturation.

The drawing explanation:

[1]-water injection well; [2]-producing well; [3]-core hole; [4]-waterflooded reservoir; [5]-the voids volume V of core sample _φ[6]-remaining oil mass volume V in the core sample _Oc[7]-remnants in the core sample mix water yield volume V _Wmfc[8]-remaining stratum water yield volume V in the core sample _Wc[9]-in the process of coring, the volatilize stratum water yield volume V of loss of core sample _Wf[10]-stratum water yield volume V in the core sample _w[11]-remnants in the core sample immerse F volume V _Mfc[12]-in the process of coring, the volatilize immersion F volume V of loss of core sample _Mff[13]-in the process of coring, the volatilize oil mass volume V of loss of core sample _Of[14]-the oil mass volume V that contains in the formation testing fluid sample _Ot[15]-the mixing water yield volume V that contains in the formation testing fluid sample _Wmft[16]-the immersion borehole wall that contains in the formation testing fluid sample near the F volume V on stratum _Mft[17]-the stratum water yield volume V that contains in the formation testing fluid sample _Wt[18]-oily, water phase permeability ratio K _Ro/ K _Rw-water saturation S _wRelation curve; [19]-the stratum oil mass volume V of core sample _o

According to shown in Figure 1, existing water injection well [1] and producing well [2] on the oil reservoir section bore common core hole [3], to obtain the saturation ratio of the waterflooded reservoir [4] of core hole [3] on oil reservoir well section between water injection well [1] and producing well [2].According to design scheme of the present invention, implementation step is: the first step is in the injection water of water injection well [1] the thickness size according to well spacing size between water injection well [1] and the core hole [3] and oil reservoir [4], a kind of tracer (as KI or sodium molybdate) that evenly adds some in a period of time guarantees that on oil reservoir [4] the well section of core hole [3] layer tester sampling method and boring sample method practicably detect the content of this tracer delicately; Second step waited that the forward position of injecting water tracer advanced core hole [3] afterwards, drill through the rock core of oil reservoir [4] well section with the double core barrel drill of diameter big (for example internal diameter is more than 120mm), and before coring, in the mud of the usefulness of coring, add a kind of of some and inject the tracer (as ammonium thiocyanate or natrium nitrosum) that water tracer must not interfere with each other to each other, guarantee to detect this tracer concentration delicately in mud sampling and the boring sample.The forward and backward mud sample of respectively obtaining of coring each time, and measure mud tracer (as ammonium thiocyanate or natrium nitrosum) concentration C in the F _MfAfter the 3rd step obtained the oil reservoir rock core, sampling was also measured the voids volume V of core sample _φ[5], the remaining oil mass volume V in the core sample _Oc[6], tracer (as KI or sodium molybdate) the quality m of water is injected on the stratum that contains in the core sample _Wc, mud tracer (as ammonium thiocyanate or natrium nitrosum) the quality m that contains in the core sample _Mfc, measure the phase permeability curve of core sample, and be converted into as shown in Figure 4 oil, water phase permeability ratio K _Ro/ K _Rw-water saturation S _wRelation curve [18].When measuring the phase permeability curve, used oil, water should adopt oil, the water sample of oil reservoir that formation tester obtains [4], or character oil, the water sample approaching with it; The 4th step got after oil reservoir [4] the well section rock core, obtained the reservoir fluid sample of rock core section immediately with formation tester, and measured the mixing water yield volume V of reservoir fluid sample _Wmft[15], water tracer (as KI or sodium molybdate) quality m is injected on the stratum that contains in the mixing water _Wt, mud tracer (as ammonium thiocyanate or natrium nitrosum) the quality m that contains in the mixing water _Mft, oil volume factor B _o(also can by high pressure physical property sample device sampling and measuring), the underground viscosity, mu of crude oil _o, water underground viscosity, mu _wThe 5th step was calculated water saturation S by the following method according to above-mentioned gained data _w: the mud tracer concentration C in the F of measuring by mud sample _Mf, by the voids volume V of core sample mensuration _φ[5], remaining oil mass volume V _Oc[6], water spike quality m is injected on the stratum _Wc, mud tracer quality m _Mfc, by the mixing water yield volume V of formation testing fluid sample mensuration _Wmft[15], water tracer quality m is injected on the stratum that contains in the mixing water _Wt, the mud tracer quality m that contains in the mixing water _Mft, oil volume factor B _o, the underground viscosity, mu of crude oil _o, water underground viscosity, mu _w, the water saturation S that the volume-based model of the pore-fluid volume-based model of the core sample that the substitution foundation is shown in Figure 2 and formation testing fluid sample shown in Figure 3 is derived _wThe stratum water yield volume V of expression formula, core sample _w[10] the remaining stratum water yield volume V in expression formula, the core sample _Wc[8] expression formula, the core sample stratum water yield volume V of loss that in the process of coring, volatilizees _Wf[9] expression formula and shunt volume f _wIn the equation group of expression formula, promptly

S _w＝V _w/V _φ

V _w＝V _wc+V _wf $V_{\mathrm{wc}}=\frac{m_{\mathrm{wc}}(V_{\mathrm{wmft}}-\frac{m_{\mathrm{mft}}}{c_{\mathrm{mf}}})}{m_{\mathrm{wt}}}$ $V_{\mathrm{wf}}=\frac{f_w\·V_{\mathrm{wc}}[C_{\mathrm{mf}}(V_{\mathrm{\φ}}-V_{\mathrm{oc}}\·B_o-V_{\mathrm{wc}})-m_{\mathrm{mfc}}]}{C_{\mathrm{mf}}\·V_{\mathrm{wc}}+m_{\mathrm{mfc}}}$ $f_w=\frac{1}{1+\frac{{\mathrm{\μ}}_w}{{\mathrm{\μ}}_o}\·\frac{K_{\mathrm{ro}}}{K_{\mathrm{rw}}}}$ With oil, water phase permeability ratio K _Ro/ k _Rw-water saturation S _wRelation curve [18] combines, and tries to achieve water saturation S by iterative method _wWith shunt volume f _w

In Fig. 1, when certain sensitive tracer (as KI or sodium aluminate) concentration of the formation water that if can obtain to indicate oil reservoir [4] in the extraction fluid of producing well [2] in advance, then needn't add tracer again at the injection water of water injection well [1], only in coring the mud of usefulness, core hole [3] adds a kind of tracer (as ammonium thiocyanate or inferior sodium nitrate) that does not interfere with each other to each other with the formation water tracer, and remaining scheme step does not repeat them here still as described in the former scheme.

Second kind of scheme: ask the waterflooded reservoir saturation ratio with common coring-test data

In the mud of usefulness of coring, add a kind of tracer, when containing tracer in the formation water, tracer and the tracer in the formation water in the mud must not disturb each other mutually, and to the sampling of the mud of the usefulness of coring, to the oil reservoir boring sample, with the reservoir fluid sampling of formation tester to the rock core section, measure the mud tracer concentration in the F, measure the voids volume of core sample, remaining oil mass volume in the core sample, remaining formation water in the core sample-F mixes water yield volume, the mud tracer quality that contains in the core sample, the oil of core sample, the water phase permeability curve, measure the oil volume factor (also can by high pressure physical property sample device sampling and measuring) of the reservoir fluid sample that formation tester obtains, the underground viscosity of crude oil, the underground viscosity of water is oil, the water phase permeability curve is converted to oil, water phase permeability ratio-water saturation relation curve.

According to the mud tracer concentration in the F of measuring by mud sample, voids volume by core sample mensuration, remaining oil mass volume, the remaining water yield volume that mixes, mud tracer quality, oil, the water phase permeability curve, the oil volume factor of measuring by the formation testing fluid sample (also can by high pressure physical property sample device sampling and measuring), the underground viscosity of underground viscosity of crude oil and water, the water saturation expression formula derived by the pore-fluid volume-based model of core sample of substitution respectively, stratum water yield volume expression formula in the core sample, remaining stratum water yield volume expression formula in the core sample, core sample volatilizees in the process of coring in the equation group of the stratum water yield volume expression formula of loss and shunt volume expression formula, with oil, water phase permeability ratio-water saturation relation curve combination goes out water saturation numerical value and shunt volume by solution by iterative method.

Below in conjunction with the example of accompanying drawing to asking the method for waterflooded reservoir saturation ratio to be described further with common coring-test data.

Fig. 1 is a method site operation schematic diagram of asking the waterflooded reservoir saturation ratio with common coring-test data.

Fig. 2 is the pore-fluid volume-based model of core sample.

Fig. 4 is the oil from core sample, the oil that the water phase permeability curve converts to, the relation curve schematic diagram of water phase permeability ratio-water saturation.

The drawing explanation:

[1]-water injection well; [2]-producing well; [3]-core hole; [4]-waterflooded reservoir; [5]-the voids volume V of core sample _φ[6]-remaining oil mass volume V in the core sample _Oc[7]-remnants in the core sample mix water yield volume V _Wmfc[8]-remaining stratum water yield volume V in the core sample _Wc[9]-in the process of coring, the volatilize stratum water yield volume V of loss of core sample _Wf[10]-stratum water yield volume V in the core sample _w[11]-remnants in the core sample immerse F volume V _Mfc[12]-in the process of coring, the volatilize immersion F volume V of loss of core sample _Mff[13]-in the process of coring, the volatilize oil mass volume V of loss of core sample _Of[18]-oily, water phase permeability ratio K _Ro/ K _Rw-water saturation S _wRelation curve; [19]-the stratum oil mass volume V of core sample _o

According to shown in Figure 1, existing water injection well [1] and producing well [2] on the oil reservoir section bore common core hole [3], to obtain the saturation ratio of the waterflooded reservoir [4] of core hole [3] on oil reservoir well section between water injection well [1] and producing well [2].According to design scheme of the present invention, implementation step is: the first step drills through the rock core of oil reservoir [4] well section with the double core barrel drill of diameter big (for example internal diameter is more than 120mm), and before coring, a kind of tracer (as ammonium thiocyanate or natrium nitrosum) that adds some in the mud of the usefulness of coring guarantees can detect this tracer concentration delicately in mud sampling and the boring sample.When containing tracer in the formation water, tracer and the tracer in the formation water in the mud must not disturb to each other mutually.The forward and backward mud sample of respectively obtaining of coring each time, and measure mud tracer (as ammonium thiocyanate or natrium nitrosum) concentration C in the F _MfAfter second step obtained the oil reservoir rock core, sampling was also measured the voids volume V of core sample _φ[5], the remaining oil mass volume V in the core sample _Oc[6], the remnants in the core sample mix water yield volume V _Wmfc[7], the mud tracer that contains in the core sample (as ammonium thiocyanate or natrium nitrosum) quality m _Mfc, measure the phase permeability curve of core sample, and be converted into as shown in Figure 4 oil, water phase permeability ratio K _Ro/ K _Rw-water saturation S _wRelation curve [18].When measuring the phase permeability curve, used oil, water should adopt oil, the water sample of oil reservoir that formation tester obtains [4], or character oil, the water sample approaching with it; The 3rd step got after oil reservoir [4] the well section rock core, obtained the reservoir fluid sample of rock core section immediately with formation tester, and measured the oil volume factor B of reservoir fluid sample _o(also can by high pressure physical property sample device sampling and measuring), the underground viscosity, mu of crude oil _o, water underground viscosity, mu _wThe 4th step was calculated water saturation S by the following method according to above-mentioned gained data _w: the mud tracer concentration C in the F of measuring by mud sample _Mf, by the voids volume V of core sample mensuration _φ[5], remaining oil mass volume V _Oc[6], the remaining water yield volume V that mixes _Wmfc[7], mud tracer quality m _Mfc, by the oil volume factor B of formation testing fluid sample mensuration _o, the underground viscosity, mu of crude oil _o, water underground viscosity, mu _w, the water saturation S that substitution is derived according to the pore-fluid volume-based model of core sample shown in Figure 2 _wThe stratum water yield volume V of expression formula, core sample _w[10] the remaining stratum water yield volume V in expression formula, the core sample _Wc[8] expression formula, the core sample stratum water yield volume V of loss that in the process of coring, volatilizees _Wf[9] expression formula and shunt volume f _wIn the equation group of expression formula, promptly

S _w＝V _w/V _φ

V _w＝V _wc+V _wf $V_{\mathrm{wc}}=V_{\mathrm{wmfc}}-\frac{m_{\mathrm{mfc}}}{c_{\mathrm{mf}}}$ $V_{\mathrm{wf}}=\frac{f_w\·V_{\mathrm{wc}}[C_{\mathrm{mf}}(V_{\mathrm{\φ}}-V_{\mathrm{oc}}\·B_o-V_{\mathrm{wc}})-m_{\mathrm{mfc}}]}{C_{\mathrm{mf}}\·V_{\mathrm{wc}}+m_{\mathrm{mfc}}}$ $f_w=\frac{1}{1+\frac{{\mathrm{\μ}}_w}{{\mathrm{\μ}}_o}\·\frac{K_{\mathrm{ro}}}{K_{\mathrm{rw}}}}$ With oil, water phase permeability ratio K _Ro/ k _Rw-water saturation S _wRelation curve [18] combines, and tries to achieve water saturation S by iterative method _wWith shunt volume f _w

The third scheme: ask the waterflooded reservoir saturation ratio with common coring-test data

Oil reservoir is cored and taken a sample, with the reservoir fluid sampling of formation tester to the rock core section, measure the voids volume of core sample, remaining oil mass volume in the core sample, remaining formation water in the core sample-F mixing water volume, the oil of core sample, the water phase permeability curve, measure the oil volume factor (also can by high pressure physical property sample device sampling and measuring) of the reservoir fluid sample that formation tester obtains, the underground viscosity of crude oil, the underground viscosity of water is oil, the water phase permeability curve is converted to profit phase permeability ratio-water saturation relation curve.

According to the voids volume of measuring by core sample, remaining oil mass volume, the remaining water yield volume that mixes, oil, the water phase permeability curve, the oil volume factor of measuring by the formation testing fluid sample (also can by high pressure physical property sample device sampling and measuring), the underground viscosity of underground viscosity of crude oil and water, the water saturation expression formula derived by the pore-fluid volume-based model of core sample of substitution respectively, the stratum oil mass volume expression formula of core sample, core sample volatilizees in the process of coring in the equation group of the oil mass volume expression formula of loss and shunt volume expression formula, with oil, water phase permeability ratio-water saturation relation curve combination goes out water saturation numerical value and shunt volume by solution by iterative method.

Below in conjunction with the embodiment of accompanying drawing to asking the method for waterflooded reservoir saturation ratio to be described further with common coring-test data.

Fig. 1 is a method site operation schematic diagram of asking the waterflooded reservoir saturation ratio with common coring-test data.

Fig. 2 is the pore-fluid volume-based model of core sample.

Fig. 4 is the oil from core sample, the oil that the water phase permeability curve converts to, the relation curve schematic diagram of water phase permeability ratio-water saturation.

The drawing explanation:

[1]-water injection well; [2]-producing well; [3]-core hole; [4]-waterflooded reservoir; [5]-the voids volume V of core sample _φ[6]-remaining oil mass volume V in the core sample _Oc[7]-remnants in the core sample mix water yield volume V _Wmfc[8]-remaining stratum water yield volume V in the core sample _Wc[9]-in the process of coring, the volatilize stratum water yield volume V of loss of core sample _Wf[10]-stratum water yield volume V in the core sample _w[11]-remnants in the core sample immerse F volume V _Mfc[12]-in the process of coring, the volatilize immersion F volume V of loss of core sample _Mff[13]-in the process of coring, the volatilize oil mass volume V of loss of core sample _Of[18]-oily, water phase permeability ratio K _Ro/ K _Rw-water saturation S _wRelation curve; [19]-the stratum oil mass volume V of core sample _o

According to shown in Figure 1, existing water injection well [1] and producing well [2] on the oil reservoir section bore common core hole [3], to obtain the saturation ratio of the waterflooded reservoir [4] of core hole [3] on oil reservoir well section between water injection well [1] and producing well [2].According to design scheme of the present invention, implementation step is: the first step with diameter the double core barrel drill of big (for example internal diameter is more than 120mm) drill through the rock core of oil reservoir [4] well section; After second step obtained the oil reservoir rock core, sampling was also measured the voids volume V of core sample _φ[5], the remaining oil mass volume V in the core sample _Oc[6], the remnants in the core sample mix water yield volume V _Wmfc[7], measure the phase permeability curve of core sample, and be converted into as shown in Figure 4 oil, water phase permeability ratio K _Ro/ K _Rw-water saturation S _wRelation curve [18].When measuring the phase permeability curve, used oil, water should adopt oil, the water sample of oil reservoir that formation tester obtains [4], or character oil, the water sample approaching with it; The 3rd step got after oil reservoir [4] the well section rock core, obtained the reservoir fluid sample of rock core section immediately with formation tester, and measured the oil volume factor B of reservoir fluid sample _o(also can by high pressure physical property sample device sampling and measuring), the underground viscosity, mu of crude oil _o, water underground viscosity, mu _wThe 4th step was calculated water saturation S by the following method according to above-mentioned gained data _wThe voids volume V that measures by core sample _φ[5], remaining oil mass volume V _Oc[6], the remaining water yield volume V that mixes _Wmfc[7], the oil volume factor B that measures by the formation testing fluid sample _o, the underground viscosity, mu of crude oil _o, water underground viscosity, mu _w, the water saturation S that substitution is derived according to the pore-fluid volume-based model of core sample shown in Figure 2 _wThe oil mass volume V of expression formula, core sample _o[19] expression formula, the core sample oil mass volume V of loss that in the process of coring, volatilizees _Of[13] expression formula and shunt volume f _wIn the equation group of expression formula, promptly

S _w＝1-(V _o/V _φ)

V _o＝V _oc·B _o+V _of

V _of＝(1-f _w)(V _φ-V _oc·B _o-V _wmfc) $f_w=\frac{1}{1+\frac{{\mathrm{\μ}}_w}{{\mathrm{\μ}}_o}\·\frac{K_{\mathrm{ro}}}{K_{\mathrm{rw}}}}$ With oil, water phase permeability ratio K _Ro/ k _Rw-water saturation S _wRelation curve [18] combines, and tries to achieve water saturation S by iterative method _wWith shunt volume f _w

The 4th kind of scheme: ask the waterflooded reservoir saturation ratio with common coring-test data

In the mud of usefulness of coring, add a kind of tracer, when containing tracer in the formation water, tracer and the tracer in the formation water in the mud must not disturb each other mutually, and to the sampling of the mud of the usefulness of coring, to the oil reservoir boring sample, with the reservoir fluid sampling of formation tester to the rock core section, measure the mud tracer concentration in the F, measure the oil of core sample, the water phase permeability curve, the oil mass volume of the reservoir fluid sample that the mensuration formation tester is obtained, mix water yield volume, the mud tracer quality that contains in the mixing water, oil volume factor (also can by high pressure physical property sample device sampling and measuring), the underground viscosity of crude oil, the underground viscosity of water is oil, the water phase permeability curve is converted to oil, water phase permeability ratio-water saturation relation curve.

According to the mud tracer concentration in the F of measuring by mud sample, oil mass volume by formation testing fluid sample mensuration, mix water yield volume, the mud tracer quality that contains in the mixing water, oil volume factor, substitution defines in the equation of deriving according to the volume-based model and the shunt volume of formation testing fluid sample, calculate near the shunt volume of oil reservoir in formation testing of the cored interval borehole wall, and with shunt volume, the underground viscosity of measuring of crude oil and the underground viscosity substitution oil of water, the relational expression of water phase permeability ratio-shunt volume, calculate fuel-displaced, water phase permeability ratio, at last by looking into oil, water phase permeability ratio-water saturation relation curve calculates the cored interval borehole wall neighbouring oil reservoir water saturation and shunt volume.

Below in conjunction with the embodiment of accompanying drawing to asking the method for waterflooded reservoir saturation ratio to be described further with common coring-test data.

Fig. 1 is a method site operation schematic diagram of asking the waterflooded reservoir saturation ratio with common coring-test data.

Fig. 3 is the volume-based model of formation testing fluid sample.

Fig. 4 is the oil from core sample, oil, the water phase permeability ratio-water saturation relation curve schematic diagram that the water phase permeability curve converts to.

The drawing explanation:

[1]-water injection well; [2]-producing well; [3]-core hole; [4]-waterflooded reservoir; [14]-the oil mass volume V that contains in the formation testing fluid sample _Ot[15]-the mixing water yield volume V that contains in the formation testing fluid sample _Wmft[16]-the immersion borehole wall that contains in the formation testing fluid sample near the F volume V on stratum _Mft[17]-the stratum water yield volume V that contains in the formation testing fluid sample _Wt[18]-oily, water phase permeability ratio K _Ro/ K _Rw-water saturation S _wRelation curve.

According to shown in Figure 1, existing water injection well [1] and producing well [2] on the oil reservoir section bore common core hole [3], to obtain the saturation ratio of the waterflooded reservoir [4] of core hole [3] on oil reservoir well section between water injection well [1] and producing well [2].According to design scheme of the present invention, implementation step is: the first step drills through the rock core of oil reservoir [4] well section with the double core barrel drill of diameter big (for example internal diameter is more than 120mm), and before coring, a kind of tracer (as ammonium thiocyanate or natrium nitrosum) that adds some in the mud of the usefulness of coring guarantees can detect this tracer concentration delicately in mud sampling and the boring sample.When in the formation water during tracer-containing, tracer and the tracer in the formation water in the mud must not interfere with each other to each other.The forward and backward mud sample of respectively obtaining of coring each time, and measure mud tracer (as ammonium thiocyanate or natrium nitrosum) concentration C in the F _MfAfter second step obtained the oil reservoir rock core, the phase permeability curve of sampling and measuring core sample, and be converted into as shown in Figure 4 oil, water phase permeability ratio K _Ro/ K _Rw-water saturation S _wRelation curve [18].When measuring the phase permeability curve, used oil, water should adopt oil, the water sample of oil reservoir that formation tester obtains [4], or character oil, the water sample approaching with it; The 3rd step got after oil reservoir [4] the well section rock core, obtained the reservoir fluid sample of rock core section immediately with formation tester, and measured the oil mass volume V of reservoir fluid sample _Ot[14], mix water yield volume V _Wmft[15], the mud tracer that contains in the mixing water (as ammonium thiocyanate or natrium nitrosum) quality m _Mft, oil volume factor B _o(also can by high pressure physical property sample device sampling and measuring), the underground viscosity, mu of crude oil _o, water underground viscosity, mu _wThe 4th step was calculated water saturation S by the following method according to above-mentioned gained data _w: the mud tracer concentration C in the F of measuring by mud sample _Mf, by the oil mass volume V of formation testing fluid sample mensuration _Ot[14], mix water yield volume V _Wmft[15], the mud tracer quality m that contains in the mixing water _Mft, oil volume factor B _o, substitution defines the following equation of deriving according to the volume-based model and the shunt volume of formation testing fluid sample shown in Figure 3, calculates near the shunt volume f of the oil reservoir formation testing of the core interval borehole wall _w, promptly $f_w=\frac{V_{\mathrm{wmft}}-\frac{m_{\mathrm{mft}}}{c_{\mathrm{mf}}}}{V_{\mathrm{ot}}\·B_o+V_{\mathrm{wmft}}-\frac{m_{\mathrm{mft}}}{c_{\mathrm{mf}}}}$ With shunt volume f _w, the underground viscosity, mu of the crude oil of mensuration _oUnderground viscosity, mu with water _wThe substitution following formula is obtained oil, water phase permeability ratio K _Ro/ K _Rw, promptly $\frac{K_{\mathrm{ro}}}{K_{\mathrm{rw}}}=(\frac{1}{f_w}-1)\frac{{\mathrm{\μ}}_o}{{\mathrm{\μ}}_w}$ At last by looking into oil, water phase permeability ratio K _Ro/ k _Rw-water saturation S _wRelation curve [18] calculates near the oil reservoir water saturation S of the core interval borehole wall _wWith shunt volume f _w

Claims (4)

1, asks the method for waterflooded reservoir saturation ratio with common coring-test data, it is characterized in that adding a kind of tracer at the injection water of waterflooded reservoir water injection well, in the mud of usefulness of coring, add another kind of tracer, tracer in the mud must not disturb each other mutually with the tracer that injects water, and to the sampling of the mud of the usefulness of coring, to the oil reservoir boring sample,, measure the mud tracer concentration C in the F with the reservoir fluid sampling of formation tester to the rock core section _Mf, the voids volume V of mensuration core sample _φ, remaining oil mass volume V _Oc, the stratum injects the tracer quality m of water _Wc, mud tracer quality m _Mfc, the oil of core sample, water phase permeability curve, and be converted to oil, water infiltration ratio k _Ro/ k _Rw-water saturation S _wRelation curve, the mixing water yield volume V of mensuration formation testing fluid sample _Wmft, the stratum that contains in the mixing water injects water tracer quality m _Wt, the mud tracer quality m that contains in the mixing water _Mft, oil volume factor B _o, the underground viscosity, mu of crude oil _oUnderground viscosity, mu with water _w, according to the above-mentioned data of measuring, the water saturation S that substitution is derived by the volume-based model of the pore-fluid volume-based model of core sample and formation testing fluid sample _wThe stratum water yield volume V of expression formula, core sample _wRemaining stratum water yield volume V in expression formula, the core sample _WcIn the process of coring, the volatilize stratum water yield volume V of loss of expression formula, core sample _WfExpression formula and shunt volume f _wIn the equation group of expression formula, promptly

S _w＝V _w/V _φ

V _w＝V _wc+V _wf $V_{\mathrm{wc}}=\frac{m_{\mathrm{wc}}(V_{\mathrm{wmft}}-\frac{m_{\mathrm{mft}}}{c_{\mathrm{mt}}})}{m_{\mathrm{wt}}}$ $V_{\mathrm{wf}}=\frac{f_w\·V_{\mathrm{wc}}[C_{\mathrm{mf}}(V_{\mathrm{\φ}}-V_{\mathrm{oc}}\·B_o-V_{\mathrm{wc}})-m_{\mathrm{mfc}}]}{C_{\mathrm{mf}}\·V_{\mathrm{wc}}+m_{\mathrm{mfc}}}$ $f_w=\frac{1}{1+\frac{{\mathrm{\μ}}_w}{{\mathrm{\μ}}_o}\·\frac{K_{\mathrm{ro}}}{K_{\mathrm{rw}}}}$ With oil, water phase permeability ratio K _Ro/ K _Rw-water saturation S _wRelation curve combines, and tries to achieve water saturation S by iterative method _wWith shunt volume f _w

2, ask the method for waterflooded reservoir saturation ratio with common coring-test data, it is characterized in that in the mud of usefulness of coring, adding a kind of tracer, when containing tracer in the formation water, tracer and the tracer in the formation water in the mud must not disturb each other mutually, and to the sampling of the mud of the usefulness of coring, to the oil reservoir boring sample,, measure the mud tracer concentration C in the F with the reservoir fluid sampling of formation tester to the rock core section _Mf, the voids volume V of mensuration core sample _φ, remaining oil mass volume V _Oc, the remaining water yield volume V that mixes _Wmfc, mud tracer quality m _Mfc, the oil of core sample, water phase permeability curve, be converted into oil, water phase permeability ratio K _Ro/ K _Rw-water saturation S _wRelation curve, the oil volume factor B of mensuration formation testing fluid sample _o, the underground viscosity, mu of crude oil _o, water underground viscosity, mu _w, according to the above-mentioned data of measuring, the water saturation S that substitution is derived by the pore-fluid volume-based model of core sample _wThe stratum water yield volume V of expression formula, core sample _wRemaining stratum water yield volume V in expression formula, the core sample _WcIn the process of coring, the volatilize stratum water yield volume V of loss of expression formula, core sample _WfExpression formula and shunt volume f _wIn the equation group of expression formula, promptly

S _w＝V _w/V _φ

V _w＝V _wc+V _wf $V_{\mathrm{wc}}=V_{\mathrm{wmfc}}-\frac{m_{\mathrm{mfc}}}{c_{\mathrm{mf}}}$ $V_{\mathrm{wf}}=\frac{f_w\·V_{\mathrm{wc}}[C_{\mathrm{mf}}(V_{\mathrm{\φ}}-V_{\mathrm{oc}}\·B_o-V_{\mathrm{wc}})-m_{\mathrm{mfc}}]}{C_{\mathrm{mf}}\·V_{\mathrm{wc}}+m_{\mathrm{mfc}}}$ $f_w=\frac{1}{1+\frac{{\mathrm{\μ}}_w}{{\mathrm{\μ}}_o}\·\frac{K_{\mathrm{ro}}}{K_{\mathrm{rw}}}}$ With oil, water phase permeability ratio K _Ro/ K _Rw-water saturation S _wRelation curve combines, and tries to achieve water saturation S by iterative method _wWith shunt volume f _w

3, ask the method for waterflooded reservoir saturation ratio with common coring-test data, it is characterized in that oil reservoir is cored and taken a sample,, measure the voids volume V of core sample with the reservoir fluid sampling of formation tester to the rock core section _φ, remaining oil mass volume V _Oc, the remaining water yield volume V that mixes _Wmfc, measure oil, the water phase permeability curve of core sample, and be converted to oil, water phase permeability ratio K _Ro/ K _Rw-water saturation S _wRelation curve, the oil volume factor B of mensuration formation testing fluid sample _o, the underground viscosity, mu of crude oil _o, water underground viscosity, mu _w, according to the above-mentioned data of measuring, the water saturation S that substitution is derived by the pore-fluid volume-based model of core sample _wThe oil mass volume V of expression formula, core sample _oIn the process of coring, the volatilize oil mass volume V of loss of expression formula, core sample _OfExpression formula and shunt volume f _wIn the equation group of expression formula, promptly

S _w＝1-(V _o/V _φ)

V _o＝V _oc·B _o+V _of

V _of＝(1-f _w)(V _φ-V _oc·B _o-V _wmfc) $f_w=\frac{1}{1+\frac{{\mathrm{\μ}}_w}{{\mathrm{\μ}}_o}\·\frac{K_{\mathrm{ro}}}{K_{\mathrm{rw}}}}$ With oil, water phase permeability ratio K _Ro/ K _Rw-water saturation S _wRelation curve combines, and tries to achieve water saturation S by iterative method _wWith shunt volume f _w

4, ask the method for waterflooded reservoir saturation ratio with common coring-test data, it is characterized in that in the mud of usefulness of coring, adding a kind of tracer, when containing tracer in the formation water, tracer and the tracer in the formation water in the mud must not disturb each other mutually, and to the sampling of the mud of the usefulness of coring, to the oil reservoir boring sample,, measure the mud tracer concentration C in the F with the reservoir fluid sampling of formation tester to the rock core section _MfMeasure oil, the water phase permeability curve of core sample, and be converted into oil, water phase permeability ratio K _Ro/ K _Rw-water saturation S _wRelation curve, the oil mass volume V of mensuration formation testing fluid sample _Ot, mix water yield volume V _Wmft, the mud tracer quality m that contains in the mixing water _Mft, oil volume factor B _o, the underground viscosity, mu of crude oil _oUnderground viscosity, mu with water _w, according to the above-mentioned data of measuring, in the equation that substitution is derived by the definition of the volume-based model of formation testing fluid sample and shunt volume, calculate near the shunt volume f of the oil reservoir formation testing rock core section borehole wall _w, promptly $f_w=\frac{V_{\mathrm{wmft}}-\frac{m_{\mathrm{mft}}}{C_{\mathrm{mf}}}}{V_{\mathrm{ot}}\·B_o+V_{\mathrm{wmft}}-\frac{m_{\mathrm{mft}}}{c_{\mathrm{mf}}}}$ With the shunt volume f that is calculated _w, the underground viscosity of crude μ of mensuration _oUnderground viscosity, mu with water _wThe substitution following formula is obtained oil, water phase permeability ratio K _Ro/ K _Rw, promptly $\frac{K_{\mathrm{ro}}}{K_{\mathrm{rw}}}=(\frac{1}{f_w}-1)\frac{{\mathrm{\μ}}_o}{{\mathrm{\μ}}_w}$ At last by looking into the ratio k of oil, water phase permeability _Ro/ K _Rw-water saturation S _wRelation curve calculates near the oil reservoir water saturation S of the core interval borehole wall _wWith shunt volume f _w

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