CN-121994851-A - Method, device, equipment and medium for predicting efficiency for sucking shale oil in lamina mode

CN121994851ACN 121994851 ACN121994851 ACN 121994851ACN-121994851-A

Abstract

The present disclosure relates to the field of unconventional shale oil and gas reservoir exploration technologies, and in particular, to a method, apparatus, device, and medium for predicting efficiency for shale oil imbibition. The method can rapidly predict the efficiency for the filtration and absorption of the lamellar shale oil, and provides an effective means for the disclosure of interaction reaction mechanism of shale reservoir rock and injection medium, oil extraction mechanism of shale reservoir rock Dan Shenxi, oil recovery mechanism of shale reservoir improvement and the like. According to the method, a seepage and oil discharge indoor test under the oil reservoir temperature and pressure condition is combined with two-dimensional nuclear magnetic analysis, the movement conditions of crude oil in different aperture spaces are distinguished according to a two-dimensional nuclear magnetic T 1 、T 2 spectrogram of nuclear magnetic diagnosis, and then a seepage and oil discharge efficiency function and an integral critical movement lower limit of each of different aperture intervals are established, so that the seepage and oil discharge efficiency function is used as a data volume model, and a method for rapidly predicting the seepage and suction efficiency of the lamellar shale oil by utilizing a two-dimensional nuclear magnetic technology under the condition of rapidly, accurately and without damaging a rock core is provided.

Inventors

TANG JIEYUN
SUN SHIQIANG
XU MINGZI
GAO YANG
HAN HONGDOU
DONG XIAODONG
FU LI
ZHANG XIANGYU
ZHANG HONG
FU WEI
LIU QICHENG
ZHANG SHUTIAN
JIANG MEIZHONG
LU YINLONG
Fu Mingze

Assignees

中国石油天然气股份有限公司

Dates

Publication Date: 20260508
Application Date: 20241106

Claims (20)

1. A method of predicting efficiency for the imbibition of a shale oil, the method comprising: The lithology of the lamellar shale oil is shale, and lamellar seams exist in the rock core; Respectively establishing a two-dimensional nuclear magnetic spectrum of saturated oil and imbibition for each core; Dividing the two-dimensional nuclear magnetic spectrum oil signal into a bound oil area, a medium pore oil area, a kerogen area and a crack oil area, wherein the crack oil area is divided into an area A with oil signal quantity smaller than a limiting value and an area B with oil signal quantity larger than or equal to the limiting value according to the limiting value; Calculating a first imbibition rate according to the saturated oil and the two-dimensional nuclear magnetic spectrum after imbibition, calculating a second imbibition rate for a kerogen region, and calculating a limiting value average value for a region B; According to the average value of the limiting value, dividing a fresh A region with the oil signal quantity smaller than the average value of the limiting value and a fresh B region with the oil signal quantity larger than or equal to the average value of the limiting value into the two-dimensional nuclear magnetic spectrum of the fresh sample; determining the oil signal quantity after the imbibition of the fresh sample according to the saturated oil signal quantity and the first imbibition rate of the fresh sample, and calculating to obtain the oil signal quantity after the imbibition of the bound oil and the mesoporous oil area of the fresh sample and the fresh area A; determining a total saturated oil signal quantity of the fresh sample and a saturated oil signal quantity of a fresh B region according to the saturated oil signal quantity of the fresh sample; And calculating to obtain the target block lamellar shale oil imbibition efficiency according to the total saturated oil signal quantity of the fresh samples, the oil signal quantity of the bound oil and the mesoporous oil of the fresh samples and the imbibition of the fresh A region, the oil signal quantity of the fresh samples and the imbibition of the kerogen region and the saturated oil signal quantity of the fresh B region.
2. The method for predicting the efficiency of shale oil imbibition according to claim 1, wherein, Taking a plurality of blocks of core of each physical property grade of the lamellar shale oil, wherein the blocks comprise: Identifying shale physical properties at different positions of a reference shaft by adopting a logging phase technology, and drilling a plurality of rock cores with the same size in each physical grade by adopting a linear cutting technology.
3. The method for predicting the efficiency of shale oil imbibition according to claim 1, wherein, Respectively establishing a two-dimensional nuclear magnetic spectrum of saturated oil and imbibition for each rock core, wherein the two-dimensional nuclear magnetic spectrum comprises the following components: And respectively measuring a T 1 spectrum and a T 2 spectrum of saturated oil by adopting two-dimensional nuclear magnetism for each core to establish a two-dimensional nuclear magnetism spectrum of saturated oil, and measuring a T 1 spectrum and a T 2 spectrum of imbibition to establish a two-dimensional nuclear magnetism spectrum of imbibition.
4. A method of predicting the efficiency of shale oil imbibition as claimed in claim 3, wherein, Determining a post-saturated oil T 1 spectrum and a T 2 spectrum to establish a post-saturated oil two-dimensional nuclear magnetic profile, comprising: Placing each core in an incubator, drying for H1H to remove residual oil in the core, loading the core into a piston container, vacuumizing for H2H to saturate the simulated shale oil, aging for H3H in the incubator, taking out the core, weighing, and measuring the T 1 spectrum and the T 2 spectrum of the saturated oil by adopting a two-dimensional nuclear magnetic resonance technology on the premise of not damaging the core.
5. The method for predicting the efficiency of shale oil imbibition of claim 4, Determining a post-saturated oil T 1 spectrum and a post-saturated oil T 2 spectrum to establish a post-saturated oil two-dimensional nuclear magnetic spectrum, and further comprising: Based on the two-dimensional nuclear magnetic spectrum after saturated oil, the software quantifies oil signal quantity W xy, saturation in different aperture spaces under the state of saturated oil of each rock core, wherein x is a T 2 spectrum coordinate value, and y is a T 1 spectrum coordinate value.
6. A method of predicting the efficiency of shale oil imbibition as claimed in claim 3, wherein, Determining the post-imbibition T 1 spectrum and the T 2 spectrum to create a post-imbibition two-dimensional nuclear magnetic profile comprising: And (3) putting each core saturated oil into a piston container, adding a imbibition medium, putting the piston container into an incubator to be set to the stratum temperature and pressurized to the reservoir pressure to carry out imbibition experiments, taking out the core after the experiment D1 days, weighing, and testing the imbibition T 1 spectrum and the imbibition T 2 spectrum by using a two-dimensional nuclear magnetic resonance technology.
7. The method for predicting the efficiency of shale oil imbibition of claim 6, Determining a post-imbibition T 1 spectrum and a post-imbibition T 2 spectrum to establish a post-imbibition two-dimensional nuclear magnetic spectrum, further comprising: based on the two-dimensional nuclear magnetic spectrum after imbibition, the software quantifies the oil signal quantity W xy, After imbibition in different aperture spaces after imbibition of each rock core, wherein x is a T 2 coordinate value and y is a T 1 coordinate value.
8. A method of predicting the efficiency of shale oil imbibition as claimed in claim 3, wherein, Dividing the two-dimensional nuclear magnetic resonance oil signals into a bound oil region, a mesoporous oil region, a kerogen region and a crack oil region, wherein the two-dimensional nuclear magnetic resonance oil signals comprise: and dividing the oil signals of the two-dimensional nuclear magnetic spectrum after saturated oil and the two-dimensional nuclear magnetic spectrum after imbibition into a constraint oil area, a mesoporous oil area, a kerogen area and a crack oil area respectively.
9. The method for predicting the efficiency of shale oil imbibition of claim 8, Dividing the two-dimensional nuclear magnetic spectrum after saturated oil and the two-dimensional nuclear magnetic spectrum after imbibition into a bound oil region, a mesoporous oil region, a kerogen region and a crack oil region respectively, wherein the two-dimensional nuclear magnetic spectrum comprises the following components: The oil-containing characteristic of the kerogen region is different from that of the bound oil and the mesoporous oil, and the crack oil region corresponds to a layer seam existing in the core, and the bound oil and the mesoporous oil region, the kerogen region and the crack oil region are distinguished through the ratio of T 1 、T 2 to T 1 /T 2 .
10. The method for predicting the efficiency of shale oil imbibition according to claim 1, wherein, Calculating a first imbibition rate according to the saturated oil and the imbibition two-dimensional nuclear magnetic spectrum, wherein the first imbibition rate comprises the following steps of: based on the two-dimensional nuclear magnetic pattern oil signals, the permeability I xy is calculated according to the following formula: I xy ＝(W xy, saturation -W xy, After imbibition )/W xy, saturation Wherein W xy, saturation represents the saturated oil signal quantity, W xy, After imbibition represents the imbibition oil signal quantity, x is the T 2 coordinate value, and y is the T 1 coordinate value.
11. The method for predicting the efficiency of shale oil imbibition of claim 10, Calculating a first imbibition rate according to the saturated oil and the imbibition two-dimensional nuclear magnetic spectrum, and further comprising: The imbibition values of the same T 1 、T 2 coordinates are averaged for each core as a first imbibition value, as shown in the following formula: Wherein I xy, Final result represents the final permeability value at point T 2 ＝x,T 1 =y, I xy,n represents the permeability at point T 2 ＝x,T 1 =y of the nth sample core, and n represents the total number of samples.
12. The method for predicting the efficiency of shale oil imbibition according to claim 1, wherein, Calculating a second imbibition rate for the kerogen region comprising: based on the two-dimensional nuclear magnetic spectrum oil signals, software quantifies the sum W Kerogen , saturation of oil signal amounts of the kerogen region in a saturated oil state and the sum W Kerogen , After imbibition of oil signal amounts of the kerogen region after imbibition, and the efficiency I xy, Kerogen for imbibition of the kerogen region is obtained through the following formula:
13. The method for predicting the efficiency of shale oil imbibition of claim 12, Calculating a second imbibition rate for the kerogen region further comprising: The average value of the imbibition efficiency of each kerogen region is taken as a second imbibition rate, and the formula is as follows: Wherein I Kerogen , Final result represents the final permeability value of the kerogen display region, I Kerogen ,n represents the permeability value of the kerogen region of the nth sample, and n represents the total number of samples.
14. The method for predicting the efficiency of shale oil imbibition according to claim 1, wherein, Taking a target block lamellar shale oil fresh sample, and measuring a two-dimensional nuclear magnetic spectrum to obtain a fresh sample saturated oil signal quantity, wherein the method comprises the following steps of: Taking a target block lamellar shale oil fresh sample, measuring a T 1 spectrum and a T 2 spectrum after saturated oil, and establishing a two-dimensional nuclear magnetic spectrum after saturated oil of the fresh sample; And determining the saturated oil signal quantity of the fresh sample according to the two-dimensional nuclear magnetic spectrum after the fresh sample is saturated with oil.
15. The method for predicting the efficiency of shale oil imbibition of claim 14, Taking a target block lamellar shale oil fresh sample, measuring a T 1 spectrum and a T 2 spectrum after saturated oil, and establishing a two-dimensional nuclear magnetic spectrum after saturated oil of the fresh sample, wherein the method comprises the following steps of: And (3) drilling a target block lamellar shale oil fresh sample by adopting a linear cutting technology, and measuring a T 1 spectrum and a T 2 spectrum of the fresh sample by adopting a two-dimensional nuclear magnetic resonance technology on the premise of not damaging a rock core.
16. The method for predicting the efficiency of shale oil imbibition according to claim 1, wherein, Determining a fresh sample total saturated oil signal amount and a fresh B zone saturated oil signal amount from the fresh sample saturated oil signal amount, comprising: Based on a two-dimensional nuclear magnetic spectrum after the fresh sample is saturated with oil, quantifying oil signal quantity W xy, Fresh and fresh in different aperture spaces under the state of each rock core fresh sample by software, and summing oil signal quantity data of all fresh sample oil signal points to obtain a fresh sample total saturated oil signal quantity W Sum total , Fresh and fresh , wherein x is a T 2 coordinate value, and y is a T 1 coordinate value; And summing the oil signal quantity data of all the fresh sample oil signal points in the fresh B region to obtain the saturated oil signal quantity W 6B, Fresh and fresh in the fresh B region.
17. The method for predicting the efficiency of shale oil imbibition according to claim 1, wherein, Determining the oil signal quantity after the imbibition of the fresh sample according to the saturated oil signal quantity and the first imbibition rate of the fresh sample, and calculating to obtain the oil signal quantity after the imbibition of the bound oil, the mesoporous oil region and the fresh A region of the fresh sample, wherein the method comprises the following steps: The oil signal quantity W xy, After imbibition after imbibition of different T 1 、T 2 coordinates is calculated as shown in the following formula: W xy, After imbibition ＝W xy, Fresh and fresh -W xy, Fresh and fresh ×I xy, Final result Wherein I xy, Final result represents the final imbibition value at T 2 ＝x,T 1 =y point, W xy, Fresh and fresh represents the fresh sample T 2 ＝x,T 1 =y point oil signal quantity, and W xy, After imbibition represents the post imbibition sample T 2 ＝x,T 1 =y point oil signal quantity; And summing the imbibition oil signal quantity data of the bound oil and the mesoporous oil region and the fresh A region to obtain the imbibition oil signal quantity W Tie oil 、 Mesoporous oil 、6A, Imbibition of the bound oil and the mesoporous oil region and the fresh A region of the fresh sample.
18. The method for predicting the efficiency of shale oil imbibition according to claim 1, wherein, Determining a post-imbibition oil signal for the kerogen region of the fresh sample based on the saturated oil signal for the fresh sample and the second imbibition rate, comprising: Summing the oil signal data of the fresh sample kerogen region to obtain W Kerogen , Fresh and fresh , and calculating the oil signal W Kerogen , After imbibition after imbibition of the kerogen region by the following formula: W Kerogen , After imbibition ＝ W Kerogen , Fresh and fresh -W Kerogen , Fresh and fresh ×I Kerogen , Final result where I Kerogen , Final result represents the final permeability value of the kerogen display region and W Kerogen , Fresh and fresh represents the sum of the oil signal amounts of the fresh sample kerogen region.
19. The method for predicting the efficiency of shale oil imbibition according to claim 1, wherein, Calculating the target block lamellar shale oil imbibition efficiency according to the total saturated oil signal quantity of the fresh samples, the oil signal quantity of the bound oil and the mesoporous oil of the fresh samples and the imbibition of the fresh A area, the oil signal quantity of the fresh samples and the imbibition of the kerogen area and the saturated oil signal quantity of the fresh B area, wherein the target block lamellar shale oil imbibition efficiency comprises the following steps: Calculating the efficiency I for the shale oil core imbibition of a fresh sample, wherein the formula is as follows: Wherein W Sum total , Fresh and fresh represents the total of the oil signal of the fresh sample, W Kerogen , After imbibition represents the total of the oil signal of the kerogen oil zone after imbibition, W Tie oil 、 Mesoporous oil 、6A, After imbibition represents the total of the oil signal of the bound oil and the mesoporous oil zone after imbibition of the fresh A zone, W 6B, Fresh and fresh represents the total of the oil signal data of all the fresh sample oil signal points of the fresh B zone, and I represents the efficiency for imbibition.
20. The device for predicting the efficiency of the imbibition of the shale oil is characterized by comprising a core preparation unit, a two-dimensional nuclear magnetic spectrum establishment unit, a region division unit, an imbibition rate calculation unit, a saturated oil signal measuring unit, an imbibition post-oil signal calculating unit and an imbibition efficiency calculation unit; The lithology of the lamellar shale oil is shale, and lamellar seams exist in the rock core; The core preparation unit is used for taking a plurality of cores of each physical property level of the lamellar shale oil; the two-dimensional nuclear magnetic spectrum building unit is used for building a two-dimensional nuclear magnetic spectrum of saturated oil and imbibition respectively for each core; The area dividing unit is used for dividing the two-dimensional nuclear magnetic spectrum oil signal into a bound oil area, a middle hole oil area, a kerogen area and a crack oil area respectively; The imbibition rate calculation unit is used for calculating a first imbibition rate according to the saturated oil and the imbibition two-dimensional nuclear magnetic spectrum; The saturated oil signal measuring unit is used for taking a target block lamellar shale oil fresh sample, measuring a two-dimensional nuclear magnetic spectrum to obtain a fresh sample saturated oil signal, and dividing a fresh A region with the oil signal smaller than the limit value average value and a fresh B region with the oil signal larger than or equal to the limit value average value into the fresh sample two-dimensional nuclear magnetic spectrum according to the limit value average value; The system comprises a saturated oil signal amount measuring unit, a saturated oil signal amount measuring unit and a saturated oil signal amount measuring unit, wherein the saturated oil signal amount measuring unit is used for determining the saturated oil signal amount of a fresh sample according to the saturated oil signal amount of the fresh sample and a first imbibition rate, and calculating to obtain the saturated oil signal amount of the fresh sample, a mesoporous oil area and a saturated oil signal amount of a fresh area A; And the efficiency calculation unit for imbibition is used for calculating and obtaining the target block lamellar shale oil imbibition efficiency according to the total saturated oil signal quantity of the fresh sample, the bound oil and mesoporous oil zone of the fresh sample, the oil signal quantity after imbibition of the fresh A zone, the oil signal quantity after imbibition of the fresh sample kerogen zone and the saturated oil signal quantity of the fresh B zone.

Description

Method, device, equipment and medium for predicting efficiency for sucking shale oil in lamina mode Technical Field The present disclosure relates to the field of unconventional shale oil and gas reservoir exploration technologies, and in particular, to a method, apparatus, device, and medium for predicting efficiency for shale oil imbibition. Background The shale oil reservoir develops a multi-scale pore throat structure, the micro-nano pore throat is widely developed, and compared with a conventional reservoir, the shale oil reservoir has higher capillary force and more obvious imbibition oil displacement effect. Imbibition oil extraction means that when the cracks around the matrix rock block are filled with water, the injected water in the cracks or large pore canals is sucked into the matrix rock block by capillary force and crude oil in the matrix is replaced, so that the redistribution of oil and water outside the matrix is realized. The imbibition exists in a plurality of key stages such as shale oil reservoir volume fracturing and water injection development, is one of important factors influencing shale oil productivity, and has important significance in improving shale oil recovery ratio by clearing imbibition characteristics and evaluating imbibition efficiency. The lithology of the sheath-type shale oil is shale, more tiny lamellar cracks exist in the core, and the lithology and the structure of the sheath-type shale oil are different from those of the interlayer-type shale oil and the shale-type shale oil. In particular, in the imbibition process, crude oil in the micro-nano pores is precipitated by imbibition, and is likely to be concentrated in the layer seams, and the measurement of the imbibition efficiency is affected. At present, the shale oil seepage and absorption efficiency is mainly characterized by adopting a self-seepage and absorption oil discharge indoor test, and the method is divided into a mass method, a volume method and a nuclear magnetic resonance method. The mass method is to treat shale rock core, then put the shale rock core into a pre-prepared imbibition solution, the mass of the rock core changes in the imbibition process, and the change of the mass along with time is monitored by an electronic balance. The volumetric method was performed using a laboratory self-made water absorption instrument. And (3) putting the treated rock core into a pre-prepared imbibition solution, and recording the change of the volume of the discharged oil along with time. The nuclear magnetic resonance method is to distinguish the fluid movement conditions in different aperture spaces according to the T 2 spectrogram of nuclear magnetic resonance diagnosis in the process of the percolation experiment. Mass and volume metering is relatively cumbersome and subject to large errors. The nuclear magnetic method has precise measurement, but the oil-water signal can not be distinguished by simple one-dimensional nuclear magnetic method, and the water signal is eliminated by adding heavy water or soaking strong water. In addition, the methods can obtain the efficiency for imbibition only by carrying out imbibition experiments for more than one month, and the core after carrying out the chemical imbibition experiments is polluted and damaged to a certain extent, so that other experiments cannot be carried out. In view of the foregoing, a technical solution for predicting the efficiency of shale oil percolation is needed. Disclosure of Invention In view of the above problems, the present disclosure provides a method, an apparatus, a device, and a medium for predicting efficiency for shale oil infiltration, which are used for solving the problems of overlong experimental period and pollution damage to a core in the existing efficiency evaluation method for shale oil infiltration. In a first aspect, a method of predicting efficiency for shale oil imbibition, the method comprising: The lithology of the lamellar shale oil is shale, and lamellar seams exist in the rock core; Respectively establishing a two-dimensional nuclear magnetic spectrum of saturated oil and imbibition for each core; Dividing the two-dimensional nuclear magnetic spectrum oil signal into a bound oil area, a medium pore oil area, a kerogen area and a crack oil area, wherein the crack oil area is divided into an area A with oil signal quantity smaller than a limiting value and an area B with oil signal quantity larger than or equal to the limiting value according to the limiting value; Calculating a first imbibition rate according to the saturated oil and the two-dimensional nuclear magnetic spectrum after imbibition, calculating a second imbibition rate for a kerogen region, and calculating a limiting value average value for a region B; According to the average value of the limiting value, dividing a fresh A region with the oil signal quantity smaller than the average value of the limiting value and a fresh B region with the oil signal