Search

CN-121976790-A - Quantitative evaluation method for multi-element granite down-the-hill reservoir

CN121976790ACN 121976790 ACN121976790 ACN 121976790ACN-121976790-A

Abstract

The invention discloses a quantitative evaluation method of a multi-element granite down-the-hill reservoir, which comprises the following steps of obtaining and counting relevant data of the age, structure and fluid of the granite down-the-hill in a target area, carrying out normalization processing on the relevant data, and obtaining a quantitative evaluation result of the development degree of the granite down-the-hill reservoir through comprehensive calculation based on all the data after normalization processing. The invention parameterizes the whole flow of each influencing factor, and constructs a set of quantitative calculation method which is simple and convenient to operate, transparent in process and repeatable to realize. The method not only can identify the maximum risk factor affecting the development of the reservoir of the down-the-hill, but also breaks through the limitation of the traditional 'black box' prediction model depending on statistical association, so that the prediction process has better interpretation. The reliability and universality of the granite subsurface reservoir prediction are improved, visual quantitative evaluation and comprehensive queuing of different subsurface target reservoir development degrees are realized, and therefore scientific basis is provided for decision making and deployment of granite subsurface oil and gas exploration.

Inventors

  • LUO WEI
  • LAN CHUNYUAN
  • HE XIAOHU
  • LIN LU
  • DAI LONG
  • HU WENYAN
  • XIA LEI
  • GUO SHIYANG
  • WU SHIJIU
  • LI RUIXUAN

Assignees

  • 中海石油(中国)有限公司海南分公司

Dates

Publication Date
20260505
Application Date
20260206

Claims (10)

  1. 1. A quantitative evaluation method for a multi-element granite down-the-hill reservoir is characterized by comprising the following steps, S1, acquiring and counting the age, construction and fluid related data of a target area granite, wherein the age data of the granite comprises the formation time and the rising stripping time of the granite, the construction data comprises the breaking density of the granite and the area of a stripping area in a key period, and the fluid data comprises the distance between the fluid data and the magma rock and the distance between the fluid data and the deep break; S2, carrying out normalization processing on the related data; and S3, based on all the data after normalization treatment, obtaining a quantitative evaluation result of the development degree of the granite buried hill reservoir through comprehensive calculation.
  2. 2. The quantitative evaluation method of multi-element granite buried hill reservoir according to claim 1, wherein in S1, the granite formation time is obtained by radioisotope dating technique, and the absolute formation time of granite is obtained by calculating the crystallization age of rock by measuring the ratio of parent and daughter by utilizing the decay law of radioisotope.
  3. 3. The quantitative evaluation method for the multi-element granite buried hill reservoir according to claim 1 or 2, wherein in S1, the Long Sheng stripping time is calculated by the following formula, T=A-t i Wherein T is the rising stripping time, ma, A is the granite forming time, ma, T i is the buried time of the down-the-road mountain target, ma.
  4. 4. The quantitative evaluation method for the multi-element granite buried hill reservoir according to claim 1 or 2, wherein in S1, the buried hill fracture density is calculated by the following formula, Wherein F is fracture density, bar/km 2 , N is fracture bar number, R is statistical radius, km.
  5. 5. The quantitative evaluation method of the multi-element granite subsurface mountain reservoir according to claim 1 or 2, wherein in the step S1, the area of the ablation zone in the critical period is determined based on the relation between the seismic profile and the stratum contact, the construction event, the interface, the in-basin ablation zone and the continuous elevation ablation zone which cause the ablation of the stratum are determined for interpretation, and the corresponding area of the ablation zone is measured based on the interpretation range.
  6. 6. The quantitative evaluation method of the multi-element granite submerged mountain reservoir according to claim 1 or 2, wherein in the step S1, when the volcanic or magma invaded body is developed at the periphery of the submerged mountain target, the distance between the submerged mountain target and the volcanic or magma invaded body closest to the submerged mountain target is the plane distance between the submerged mountain target and the volcanic or magma invaded body, and when the volcanic or magma invaded body is not developed at the periphery of the submerged mountain target, the distance between the submerged mountain target and the magma rock is not considered.
  7. 7. The quantitative evaluation method of the multi-element granite buried hill reservoir according to claim 1 or 2, wherein in the step S1, when a plurality of deep breaks develop near the target, the distance between the buried hill target and the deep break closest to the buried hill target is the perpendicular distance between the buried hill target and the plane of the deep break.
  8. 8. The quantitative evaluation method for the multi-element granite buried hill reservoir according to claim 1 or 2, wherein in the step S2, the normalization processing formula is as follows, Wherein, the The data normalization value, X is the statistic value of the data; A statistical minimum value for a piece of data; Is a statistical maximum of some item of data.
  9. 9. The quantitative evaluation method of the multi-element granite buried hill reservoir according to claim 1 or 2, wherein in the step S3, the calculation formula of the quantitative evaluation result of the granite buried hill reservoir development degree is as follows, P=A 1 +T 1 +F 1 +S 1 +D 1 +D 2 Wherein P is a comprehensive score of the development degree of the reservoir, A 1 is a granite formation time normalization value, A 1 is a dimensionless value, T 1 is a rising stripping time normalization value, F 1 is a fracture density normalization value, F 1 is an area normalization value, D 1 is a distance normalization value with the magma rock, and D 2 is a distance normalization value with the deep fracture, and the dimensionless value.
  10. 10. A multi-element granite down-the-hill reservoir quantitative evaluation system is characterized in that the multi-element granite down-the-hill reservoir quantitative evaluation method of any one of claims 1 to 9 is operated.

Description

Quantitative evaluation method for multi-element granite down-the-hill reservoir Technical Field The invention belongs to the technical field of oilfield exploration, and particularly relates to a quantitative evaluation method for a multi-element granite buried hill reservoir. Background With the continuous expansion of global oil and gas exploration to deep-ultra deep and complex down-the-hill reservoirs, granite down-the-hill has become an important successor field and exploration hotspot. Unlike conventional clastic rock reservoirs, granite down-the-hill reservoirs have extremely strong heterogeneity, and the formation of the reservoir space is the result of long-term, multi-element geologic action superposition modification. Although the traditional single factor evaluation method can solve the problem of reservoir prediction of the submarine mountain within a certain range, the method is not suitable for the field of the submarine mountain of granite due to insufficient consideration of influencing factors, so that the prediction success rate fluctuates greatly and the exploration risk is high. In the aspect of granite down-the-hole reservoir prediction, although the method aiming at crack prediction, weathering crust recognition, longitudinal reservoir zoning and lithology lithofacies discrimination is formed, the method has the characteristics that firstly, the technologies focus on single elements of the reservoir, such as relying on seismic data or imaging logging to perform crack prediction or developing lithology lithofacies classification based on core and logging data, secondly, the method is often mainly characterized by qualitative or semi-quantitative classification, the reservoir prediction discrimination results are mainly classified into favorable, favorable and unfavorable classes and lack quantitative data, thirdly, the key reservoir elements of fluid transformation are mostly considered less, or only qualitative description is performed, and the influence degree of fluid activities on down-hole reservoirs in different areas cannot be represented quantitatively. Finally, the method is limited by the characteristics, and the prior art can predict the reservoir under the technical construction area or simple geological conditions, but has weak universality and high extrapolation utilization risk, and particularly when facing the granite down-hill with long weathering time, complex structure and strong fluid activity, the prediction result and the actual drilling effect are often deviated greatly, so that the urgent requirements of the current down-hill exploration on the reservoir prediction precision and reliability cannot be met. Therefore, the research and development of the multi-factor and quantitative granite down-the-hill reservoir prediction method has important significance in improving the success rate of granite down-the-hill reservoir prediction and comparing and optimizing down-the-hill targets. Disclosure of Invention The invention aims to solve the problem of providing a quantitative evaluation method for a multi-element granite down-the-hill reservoir, which considers the influence of the formation age, the late construction activity and the deep fluid action of the down-the-hill reservoir on the down-the-hill reservoir development, has the characteristics of high reliability, simple and convenient operation, wide applicability and quantification, and can intuitively and quantitatively develop the comprehensive queuing and evaluation of the development degrees of different down-the-hill target reservoirs, thereby providing scientific basis for decision and deployment of oil and gas exploration of the granite down-the-hill. In order to solve the technical problems, the technical proposal adopted by the invention is that the quantitative evaluation method for the multi-element granite buried hill reservoir comprises the following steps, S1, acquiring and counting the age, construction and fluid related data of a target area granite, wherein the age data of the granite comprises the formation time and the rising stripping time of the granite, the construction data comprises the breaking density of the granite and the area of a stripping area in a key period, and the fluid data comprises the distance between the fluid data and the magma rock and the distance between the fluid data and the deep break; S2, carrying out normalization processing on the related data; and S3, based on all the data after normalization treatment, obtaining a quantitative evaluation result of the development degree of the granite buried hill reservoir through comprehensive calculation. Further, in the step S1, the granite formation time is obtained by radioisotope dating technique, and the crystal age of the rock is calculated by measuring the ratio of parent and daughter by utilizing the decay law of radioisotope, thereby obtaining the absolute formation time of granite. Further, in the step S1, the