CN-121994852-A - Method, device, equipment and medium for predicting efficiency for imbibition of massive shale oil

CN121994852ACN 121994852 ACN121994852 ACN 121994852ACN-121994852-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 massive shale oil imbibition. According to the method, the content of oil in different pore-size intervals after the saturated oil is pressurized by the core is rapidly quantified through a two-dimensional nuclear magnetic resonance technology under the condition of not damaging the core, and then the respective imbibition oil extraction efficiency function and the whole critical lower limit of the different pore-size intervals of the blocky shale under the stratum condition established by the method are utilized, so that the imbibition oil extraction efficiency of the whole shale core can be rapidly, accurately and quantitatively represented. The method can be used for rapidly, accurately and uninjured determination of the efficiency for shale oil core imbibition under the condition of no harm to the core, and provides an effective means for revealing interaction reaction mechanisms of shale reservoir rock and injection media, oil extraction mechanisms of shale reservoir rock Dan Shenxi, oil recovery mechanisms of shale reservoir improvement and the like. The method has important engineering value and scientific significance for promoting the effective and economic development of shale reservoirs.

Inventors

TANG JIEYUN
XU MINGZI
GAO YANG
CUI XIANGDONG
YAN HONGXING
HAN HONGDOU
DONG XIAOYU
ZHANG XIANGYU
ZHANG HONG
ZHANG SHUTIAN
JIANG MEIZHONG
LU YINLONG
FU WEI
Fu Mingze
SUN SHIQIANG

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 oil imbibition of a shale block, the method comprising: taking a plurality of cores of each physical property level of the massive shale oil; Establishing a two-dimensional nuclear magnetic spectrum for each core; dividing the two-dimensional nuclear magnetic spectrum oil signal into a bound oil region, a mesoporous oil region and a kerogen region; Calculating a first imbibition rate according to the two-dimensional nuclear magnetic spectrum; Taking a target block shale fresh sample, and measuring a two-dimensional nuclear magnetic spectrum to obtain a fresh sample saturated oil signal quantity; Determining a fresh sample bound oil and a medium pore oil zone imbibition oil signal quantity according to the fresh sample saturated oil signal quantity and the first imbibition rate; And calculating to obtain the target block shale oil imbibition efficiency according to the total saturated oil signal quantity of the fresh sample, the oil signal quantity of the fresh sample after imbibition of the bound oil and the mesoporous oil region and the oil signal quantity of the fresh sample after imbibition of the kerogen region.
2. The method for predicting the efficiency of shale oil imbibition of claim 1, wherein, Taking a plurality of cores of each physical property level of massive shale oil, comprising: 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 of claim 1, wherein, Establishing a two-dimensional nuclear magnetic spectrum for each core, including: 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 for predicting 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 wherein, 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: The software quantifies the oil signal quantity W xy, saturation in different aperture spaces under the saturated oil state 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 for predicting 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, wherein, 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: 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 for predicting efficiency of shale oil imbibition as claimed in claim 3, wherein, Dividing the two-dimensional nuclear magnetic pattern oil signal into a bound oil region, a mesoporous oil region and a kerogen region respectively, wherein the two-dimensional nuclear magnetic pattern oil signal comprises: 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 bound oil area, a mesoporous oil area and a kerogen area respectively.
9. The method for predicting the efficiency of shale oil imbibition of claim 8, wherein, Dividing the two-dimensional nuclear magnetic spectrum after saturated oil and the two-dimensional nuclear magnetic spectrum oil signal after imbibition into a bound oil region, a mesoporous oil region and a kerogen region respectively, wherein the two-dimensional nuclear magnetic spectrum oil signal comprises: The oil-containing characteristics of the kerogen region are different from those of the bound oil and the mesoporous oil, and the bound oil, the mesoporous oil region and the kerogen region are distinguished by the ratio of T 1 、T 2 to T 1 /T 2 .
10. The method for predicting the efficiency of shale oil imbibition of claim 1, wherein, Calculating a first imbibition rate from the two-dimensional nuclear magnetic pattern, comprising: 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, wherein, Calculating a first imbibition rate according to the two-dimensional nuclear magnetic resonance 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 block core, and n represents the total number of samples.
12. The method for predicting the efficiency of shale oil imbibition of 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, wherein, 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 of claim 1, wherein, Taking a target block shale fresh sample, and measuring a two-dimensional nuclear magnetic spectrum to obtain a saturated oil signal quantity of the fresh sample, wherein the method comprises the following steps: Taking a target block shale 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 wherein, Taking a target block shale fresh sample, measuring a T 1 spectrum and a T 2 spectrum after saturated oil to establish a two-dimensional nuclear magnetic spectrum after fresh sample saturated oil, wherein the method comprises the following steps of: And (3) drilling a target block shale 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 of claim 1, wherein, Determining a fresh sample total saturated oil signal from the fresh sample saturated oil signal, comprising: And quantifying the oil signal quantity W xy, Fresh and fresh in different aperture spaces under the state of each core fresh sample by software, and summing the 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.
17. The method for predicting the efficiency of shale oil imbibition of claim 1, wherein, Determining a fresh sample bound oil and a post-imbibition oil signal for a mesoporous oil region from the fresh sample saturated oil signal and the first imbibition rate, comprising: 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 all imbibed oil signal quantity data of the bound oil and mesoporous oil region W xy, After imbibition data body to obtain the oil signal quantity W Tie oil 、 Mesoporous oil , After imbibition of the fresh sample bound oil and mesoporous oil region imbibed.
18. The method for predicting the efficiency of shale oil imbibition of 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 of claim 1, wherein, According to the total saturated oil signal quantity of the fresh sample, the oil signal quantity of the fresh sample after imbibition of the bound oil and the mesoporous oil zone and the oil signal quantity of the fresh sample after imbibition of the kerogen zone, the efficiency for imbibition of the target block shale oil is calculated and obtained, and the method 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 , After imbibition represents the total of the oil signal of the bound oil and the mesoporous oil zone after imbibition, and I represents the efficiency for imbibition.
20. The device for predicting the imbibition efficiency of the massive shale oil is characterized by comprising a control sample imbibition rate measuring unit and a fresh sample imbibition efficiency measuring unit; the control sample permeability measuring unit is used for taking a plurality of rock cores of each physical property level of the massive shale oil; the control sample permeability measuring unit is also used for establishing a two-dimensional nuclear magnetic spectrum for each rock core; The control sample permeability measuring unit is further used for dividing the two-dimensional nuclear magnetic resonance spectrum oil signals into a bound oil area, a mesoporous oil area and a kerogen area respectively; the control sample imbibition rate measuring unit is also used for calculating the first imbibition rate according to the two-dimensional nuclear magnetic spectrum; The system comprises an efficiency measuring unit for fresh sample infiltration, a total saturated oil signal amount measuring unit and a total saturated oil signal amount measuring unit, wherein the efficiency measuring unit is used for taking a target block shale fresh sample, measuring a two-dimensional nuclear magnetic spectrum and obtaining a fresh sample saturated oil signal amount; The efficiency measuring unit for the fresh sample imbibition is also used for determining the oil signal quantity after the imbibition of the fresh sample constraint oil and the mesoporous oil zone according to the saturated oil signal quantity of the fresh sample and the first imbibition rate; The efficiency measuring unit for the fresh sample imbibition is also used for calculating and obtaining the efficiency for the target block shale oil imbibition according to the total saturated oil signal quantity of the fresh sample, the oil signal quantity after imbibition of the bound oil and the mesoporous oil zone of the fresh sample and the oil signal quantity after imbibition of the kerogen zone of the fresh sample.

Description

Method, device, equipment and medium for predicting efficiency for imbibition of massive shale oil 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 massive shale oil imbibition. Background Shale oil gas resources are widely distributed, the potential of resources is huge, and the shale oil gas resources are important strategic alternative energy sources, but realizing scale benefit development is still the biggest problem facing at present. 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. Shale (blocky) lithology is shale, and the bedding does not develop. 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 a long time (more than 1 month), and the core after carrying out the chemical agent imbibition experiments is polluted and damaged to a certain extent, and other experiments cannot be carried out, so that the method for rapidly predicting the efficiency for massive shale oil imbibition by utilizing the two-dimensional nuclear magnetic technology is provided for overcoming the defects in the existing shale oil imbibition efficiency evaluation method. In view of the foregoing, a technical solution for rapidly predicting the efficiency of oil seepage and absorption of massive shale is needed. Disclosure of Invention In view of the above problems, the present disclosure provides a method, apparatus, device and 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 imbibition of a bulk shale oil, the method comprising: taking a plurality of cores of each physical property level of the massive shale oil; Establishing a two-dimensional nuclear magnetic spectrum for each core; dividing the two-dimensional nuclear magnetic spectrum oil signal into a bound oil region, a mesoporous oil region and a kerogen region; Calculating a first imbibition rate according to the two-dimensional nuclear magnetic spectrum; Taking a target block shale fresh sample, and measuring a two-dimensional nuclear magnetic spectrum to obtain a fresh sample saturated oil signal quantity; Determining a fresh sample bound oil and a medium pore oil zone imbibition oil signal quantity according to the fresh sample saturated oil signal quantity and the first imbibition rate; And calculating to obtain the target block shale oil imbibition efficiency according to the total saturated oil signal quantity of the fresh sample