CN-121993148-A - Method for optimizing heavy oil reservoir thermochemical huff and puff efficiency improving process

CN121993148ACN 121993148 ACN121993148 ACN 121993148ACN-121993148-A

Abstract

The invention provides a method for optimizing a heavy oil reservoir thermochemical throughput efficiency improving process, which comprises the steps of 1, collecting geological data, establishing a numerical model, calculating to obtain a relation curve of different factors and productivity, 2, fitting the relation curve to obtain a relation formula of different factors and productivity, 3, calculating the influence of different factors according to the reservoir development condition, 4, calculating the influence proportion of different factors on productivity by using a hierarchical analysis method, and 5, optimizing the steam throughput efficiency improving process according to the influence degree. The method for optimizing the thermochemical huff and puff efficiency improving process of the heavy oil reservoirs realizes quantitative comparison among different productivity influencing factors of different types of heavy oil reservoirs, realizes quantitative evaluation of the influence of different factors on productivity by combining an analytic hierarchy process, optimizes thermochemical medicaments according to the duty ratio of the different factors, and improves the steam huff and puff development effect of multiple times.

Inventors

ZHANG ZHAOXIANG
LIU MING
YIN FANGHAO
HAO TINGTING
HE XU
TONG TONG
FENG HAISHUN
HAN YANHUI
YI ZHAOLONG

Assignees

中国石油化工股份有限公司
中国石油化工股份有限公司胜利油田分公司

Dates

Publication Date: 20260508
Application Date: 20241104

Claims (11)

1. A method of optimizing a heavy oil reservoir thermochemical huff and puff efficiency enhancing process, the method of optimizing a heavy oil reservoir thermochemical huff and puff efficiency enhancing process comprising: step 1, collecting geological data, establishing a numerical simulation model, and calculating to obtain relation curves of different factors and productivity; step2, fitting the relation curve to obtain relation formulas of different factors and productivity; Step 3, calculating the influence of different factors according to the oil reservoir development condition; Step 4, calculating the influence duty ratio of different factors on productivity by using an analytic hierarchy process; and 5, according to the influence degree, a steam throughput efficiency improvement process is preferred.
2. The method for optimizing a heavy oil reservoir thermochemical throughput efficiency improving process according to claim 1, wherein in step 1, reservoir physical properties of a target block are collected, a numerical simulation model is established, productivity is used as an evaluation index, and a relation curve between different factors and productivity is calculated.
3. The method of claim 2, wherein in step 1, different factors include pressure, saturation, permeability, porosity, and the like, and the selection may be performed according to a site point of interest, and the selection may be performed according to a darcy formula, and the reservoir productivity calculation formula is: where q is the reservoir capacity, k is the absolute permeability, kr is the relative permeability, P is the pressure differential between the deep reservoir and the bottom of the huff-puff well, μ is the crude oil viscosity, and L is the percolation distance.
4. The method for optimizing a heavy oil reservoir thermochemical throughput efficiency improving process according to claim 1, wherein in step 2, a relation curve of different factors and productivity obtained in step 1 is fitted to obtain the following power function relation: Wherein r 1 、r 2 、r 3 is the ratio of permeability, saturation and reservoir pressure change after the reservoir pressure change, Δk, Δs and Δp are the ratio of permeability, saturation and reservoir pressure change, a 1 、a 2 、a 3 is the coefficient of power function, obtained by data fitting software, b 1 、b 2 、b 3 is the index of power function, obtained by data fitting software.
5. The method for optimizing a heavy oil reservoir thermochemical throughput efficiency improving process according to claim 4, wherein in step 3, the relational expression obtained in step 2 is derived to obtain the change rate of the influence of different factors on productivity; where r 1 ′、r 2 ′、r 3 ' is the effect of permeability, saturation, reservoir pressure on the rate of change of capacity.
6. The method for optimizing a heavy oil reservoir thermochemical throughput efficiency improving process according to claim 1, wherein in step 4, the influence degree of different factors obtained in step 3 is normalized to obtain the influence of different factors on productivity under the current reservoir development condition.
7. The method for optimizing heavy oil reservoir thermochemical throughput efficiency improving process according to claim 6, wherein in step 4, the effect of magnitude and dimension is eliminated, calculation is simplified, model precision is improved, transverse comparison is carried out on different reservoirs, a analytic hierarchy process can be adopted in the calculation process, the analytic hierarchy process is a system method which takes a complex multi-objective decision problem as a system, decomposes targets into a plurality of targets or criteria, further decomposes the targets into a plurality of layers of multiple indexes, calculates single-order and total-order of the layers through a qualitative index fuzzy quantization method, and takes the single-order and the total-order as a system method for objective and multi-scheme optimization decision.
8. The method for optimizing a heavy oil reservoir thermochemical throughput efficiency process according to claim 1, wherein in step 5, the steam throughput efficiency process is optimized according to the influence of different factors calculated in step 4 on the productivity, and the optimization method is that when the influence of a certain factor on the productivity exceeds a threshold value, the corresponding efficiency process is required.
9. The method for optimizing the heavy oil reservoir thermochemical throughput efficiency improving process according to claim 8, wherein in step 5, the optimizing method can be divided into three cases of single measures, double measures and three measures, wherein the single measures are that a single factor exceeds a threshold value, the plugging agent, the viscosity reducer or the gas is selected to be injected singly, the double measures are that two factors exceed the threshold value, the two processes are selected to be combined for implementation, the three measures are that all three factors exceed the threshold value, and the plugging agent, the viscosity reducer and the gas are selected to be injected in combination.
10. The system for optimizing the heavy oil reservoir thermochemical huff and puff efficiency improving process is characterized in that the system for optimizing the heavy oil reservoir thermochemical huff and puff efficiency improving process adopts the method for optimizing the heavy oil reservoir thermochemical huff and puff efficiency improving process according to any one of claims 1 to 9, preferably thermochemical medicament, and improves the steam huff and puff development effect for multiple times.
11. A computer readable storage medium, characterized in that it comprises a stored computer program, wherein the computer program, when run, controls the apparatus in which the computer readable storage medium is located to carry out a method of a preferred heavy oil reservoir thermochemical throughput performance process as claimed in any one of claims 1 to 9.

Description

Method for optimizing heavy oil reservoir thermochemical huff and puff efficiency improving process Technical Field The invention relates to the technical field of oilfield development, in particular to a method for optimizing a heavy oil reservoir thermochemical huff and puff efficiency improving process. Background The thick oil resource reserves are rich and account for more than 70% of the total world oil reserves. At present, the domestic thick oil resources are mainly developed by steam huff and puff, generally enter a multi-round huff and puff stage, face various problems of limited steam wave and radius, low reservoir pressure, serious steam channeling and the like, and finally have poor oil reservoir development effect and economic benefit, and are not beneficial to the yield increase and stable yield of the national crude oil. The thermochemical technology is an important effect improving method for steam huff and puff, and the aim of increasing reservoir pressure, adjusting steam absorption profile, expanding steam wave, improving oil washing efficiency and the like is fulfilled by assisting in injecting chemical agents in the steam huff and puff process. Different chemical agents correspond to different effectiveness improving processes, namely, blocking agents such as foam, gel and the like, blocking a steam channeling channel through pre-injection, promoting the steam to flow around after the subsequent injection, so that the steam wave range is enlarged, viscosity reducing agents such as oil solubility, water solubility and the like reach the deep part of an oil reservoir under the displacement of the steam through pre-injection, reducing the viscosity of crude oil at the front edge of the steam, enlarging the oil drainage radius, and gases such as nitrogen, flue gas and the like, wherein the pre-injection or the co-injection improves the pressure of the oil reservoir, and increases the power of the crude oil flowing back to the bottom of the well. In the actual production process, the chemical agent is injected singly or in combination, so that the production cost is reduced, and the steam huff and puff development effect of the heavy oil reservoir is improved. The current efficiency improving process is selected more by virtue of field experience, namely after steam channeling is formed between huff-puff wells, plugging agent is injected for profile control, when the turn is low, oil washing agent is injected to reduce the oil saturation of a near-wellbore zone, when the turn is high, viscosity reducer is injected to enlarge the oil drainage radius, and when the pressure of the reservoir is relatively low, energized gas is injected to improve the pressure of the reservoir. When the development effect is poor due to multiple factors, theoretical guidance is lacking in selection of the efficiency improving process, pertinence is weakened, effectiveness is reduced, and improvement of the steam throughput development effect of the heavy oil reservoir is not facilitated. The Chinese patent application with the application number of CN201210432484.8 relates to a multi-pass huff-puff post-mining method of a thin heavy oil reservoir, which comprises the steps of 1, injecting steam into a well, 2, simultaneously injecting nitrogen and a microemulsion viscosity reducer, 3, stewing the well, and 4, starting a steam injection pipe column, downloading a production pipe column and transferring and pumping production. The patent proposes a method for enhancing thermal recovery by utilizing nitrogen and a microemulsion viscosity reducer to assist steam, wherein the method adopts a combination of nitrogen and the viscosity reducer, but the oil reservoir adaptability lacks theoretical calculation, and is not quantitatively compared with other efficiency improving processes. In the Chinese patent application with the application number of CN202010401535.5, a step design method for multi-component directional viscosity reduction of thick oil after multi-round throughput is related. The method comprises the steps of 1, calculating an oil layer temperature change curve along the radial direction of a huff-puff well, 2, partitioning the temperature curve, 3, obtaining the radius and the area of the partition, 4, comparing the areas of the partition, determining the medium injection and the injection sequence of the next cycle, and 5, establishing a multi-step directional viscosity reduction mode of steam huff-puff. The patent proposes a method for precisely utilizing residual oil, improving steam heat utilization rate and improving steam huff and puff development effect by utilizing an oil layer temperature change curve along the radial direction of a huff and puff well to realize fine division of an oil layer. In the Chinese patent application with the application number of CN202111236799.0, the method for evaluating the profile control potential of nitrogen foam after the heavy oil reservoir is hugged in multip