scholarly journals A New Method to Determine the Lower Limit of Reservoir Physical Properties—Corrected Minimum Flow Pore-throat Radius Method

2021 ◽  
Vol 290 ◽  
pp. 03004
Author(s):  
Jinyou Dai ◽  
Lixin Lin ◽  
Rui Wang
Keyword(s):  
Physical Properties ◽  
Lower Limit ◽  
Traditional Method ◽  
Oil And Gas ◽  
Correction Method ◽  
New Method ◽  
Pore Throat ◽  
Throat Radius ◽  
Minimum Flow ◽  
Gas Accumulation

The lower limit of reservoir physical properties is an important parameter for identifying reservoirs and determining effective thickness in reserves evaluation, and is also an important basis for selecting perforated test intervals in oilfield exploration and development. There are many methods to determine the lower limit of reservoir physical properties, and the minimum flow pore throat radius method is one of the commonly used methods. The method uses 0.1μm as the minimum flow pore-throat radius, and uses this to calibrate the lower limit of reservoir physical properties. However, according to the water film theory, the minimum radius of the reservoir's flowing pore throat is not a definite value, but varies with the displacement dynamics. Therefore, there is no exact basis for using 0.1μm as the minimum flow pore-throat radius, so it needs to be corrected. To this end, a new method for determining the lower limit of reservoir physical properties—the corrected minimum flow pore-throat radius method is proposed. The correction method comprehensively considers the factors of oil and gas accumulation dynamics, and determines the lower limit of reservoir physical properties by obtaining the minimum flow pore-throat radius value suitable for oil and gas accumulation dynamics. A case study of Chang 63 reservoir in A Oilfield shows that the minimum flow pore radius of oil and gas determined by the correction method is 0.08 μm, and the lower limit of reservoir physical properties (porosity 9.1%, permeability 0.117 × 10-3 μm2). The traditional method has a minimum flow pore-throat radius of 0.1 μm and a lower limit of reservoir physical properties (porosity of 9.8% and permeability of 0.133 × 10-3 μm2). Due to full consideration of the impact of oil and gas accumulation dynamics, the minimum flow pore-throat radius determined by the correction method is more reliable than the traditional method, and the lower limit of the reservoir physical property calibrated by it has practical significance.

The Law of Reservoir Property Change both before and after Water Flooding in Liaohe Oilfield

2015 ◽  
Vol 733 ◽  
pp. 31-34
Author(s):  
Yan Zhang ◽  
Shuang Yu
Keyword(s):  
Physical Properties ◽  
Water Flooding ◽  
Pore Throat ◽  
Reservoir Properties ◽  
Throat Radius ◽  
Liaohe Oilfield ◽  
Before And After ◽  
Mouth Bar ◽  
Oilfield Development ◽  
Distributary Channel

In order to explore the change laws of physical properties and pore throat radius of reservoir both before and after water flooding to guide the oilfield in-depth fluid diversion, the reservoir properties are analyzed on the basis of core data of early exploratory well and inspection well in the middle and later stages of oilfield development. The theory of reservoir geology and development geology is used to study the change laws of reservoir properties both before and after water flooding in May 20th Development Area of Liaohe oilfield. The research result indicates that reservoir physical properties and pore throat radius have changed in the different period and different microfacies types of sand body [1-3].The permeability is changed far outweigh porosity in the physical properties of reservoir. And with the increase of time, the biggest change is the porosity and permeability of distributary channel, the next are margin of channels, mouth bar. The thin layer of channels and distal bar of physical properties have changed lesser or not. The pore throat radius has declined following distributary channel, mouth bar, thin layer of channels and distal bar in the sedimentary microfacies [4-5].The study results are helpful for the establishment of production measures at the later stage of oilfield development.

scholarly journals A Comparative Study on Microscopic Characteristics of Volcanic Reservoirs in the Carboniferous Kalagang and Haerjiawu Formations in the Santanghu Basin, China

2021 ◽  
Vol 9 ◽  
Author(s):  
Weiming Wang ◽  
Weihao La ◽  
Tanguang Fan ◽  
Xiongfei Xu ◽  
Yingnan Liu ◽  
...  
Keyword(s):  
Physical Properties ◽  
Oil And Gas ◽  
Volcanic Rocks ◽  
High Yield ◽  
Tight Oil ◽  
Pore Throat ◽  
Pore Structures ◽  
Mercury Injection ◽  
Oil Flow ◽  
Volcanic Reservoirs

Self-jetting high-yield oil flow was obtained from Ma 67 and Ma 36 wells drilled in the volcanic reservoirs of the Haerjiawu Formation in the Santanghu Basin, China. This has shifted the prospectors’ attention to the Haerjiawu Formation from the Kalagang Formation, which is generally considered to have favorable physical properties. To further explain the geological reasons why oil flow can jet itself from the volcanic rocks in the Haerjiawu Formation with poor physical properties, this study carries out a systematic comparison on the microscopic pore structures of volcanic rocks through unconventional tests such as low-temperature nitrogen adsorption, high-pressure mercury injection, and constant-rate mercury injection based on the analyses of physical properties and minerals. The results obtained are as follows. The volcanic rocks of the Kalagang Formation have relatively high pore permeability. However, their micropores have a wide distribution range of pore size and feature highly meandering structures and strong heterogeneity. Meanwhile, small pore throats connect large pores in the volcanic rocks, resulting in a relatively high pore/throat ratio. All these are conducive to the occurrence of tight oil and gas but unfavorable for the flow of oil and gas. The volcanic rocks in the Haerjiawu Formation have relatively low volcanic permeability. However, small pores connect large pore throats in the volcanic rocks; thus, leading to a relatively low pore/throat ratio. Meanwhile, the volcanic rocks feature low meandering structures, strong homogeneity, and high connectivity. All these are favorable for the formation of tight oil and gas reservoirs. These assessment results also indicate that the assessment indices of tight volcanic reservoirs should not only include porosity and permeability. Instead, more attention should be paid to the microscopic pore structures, and it is necessary to analyze the charging and flow of tight oil from the configuration of pores and pore throats. This study not only explains the geological factors of the wells with self-jetting high-yield oil flow in the Haerjiawu Formation from the perspective of microscopic pore structures but also provides a new idea and comparison method for the assessment of tight reservoirs in other areas.

Evaluation method for low to ultralow permeability reservoirs based on pore-throat structure: A case study in the eastern Nanpu Sag, Bohai Bay Basin, China

2020 ◽  
pp. 1-47
Author(s):  
Xiaodong Zhao ◽  
Shilin Wang ◽  
Jingxu Yang ◽  
Boming Zhang ◽  
Liang Li ◽  
...  
Keyword(s):  
Physical Properties ◽  
Evaluation Method ◽  
Maximum Pressure ◽  
Bohai Bay ◽  
Pore Throat ◽  
Bohai Bay Basin ◽  
Throat Radius ◽  
Thin Sections ◽  
Nanpu Sag ◽  
Ultralow Permeability

The pore-throat structure of low to ultralow permeability reservoirs is complex, causing the permeability to vary greatly under similar porosity conditions. And the pore-throat structures are the key factors that controlled the physical properties of such kind of reservoirs. Therefore, conventional reservoir evaluation methods can hardly meet the research needs of low to ultralow permeability reservoir exploration and development. We conducted our research on Paleogene Shahejie and Neogene Dongying low to ultralow permeability reservoirs in the eastern Nanpu Sag of the Bohai Bay Basin in order to address this issue. Cores, thin sections and scanning electron microscope were used to analyze the pore-throat structures in order to determine the characteristics of low to ultralow permeability reservoirs and a new parameter for evaluating low to ultralow permeability reservoirs is proposed. The results of this research show that primary pores, secondary pores and micro-fractures are developed in the study area, and the pore-throat shape is mainly flaky or curved flaky. The microscopic pore-throat structure controlled the reservoir physical properties and fluid mobility of these reservoirs, the permeabilities of these reservoirs are dependent on the pore throats, and the correlation between connected pores and permeability is strong. Based on the analysis of the pore-throat structure, as well as the maximum mercury saturation and the residual mercury saturation at the maximum pressure and the minimum pressure obtained by the mercury injection test, an evaluation of the reservoir by using the mobility parameter of fluid is proposed, and the pore-throat radius R15 obtained by the mercury intrusion experiment has the best correlation with the fluid mobility parameters. The mobility parameters of fluid can effectively improve the accuracy of logging interpretation of low to ultralow permeability reservoirs and provide a scientific basis for the scale stimulation and effective development of low to ultralow permeability reservoirs.

scholarly journals A new method of multi-beam real-time attitude compensation data processing

2020 ◽  
Vol 206 ◽  
pp. 01014
Author(s):  
Zhang Yonghou ◽  
Xiao Fumin ◽  
Jin Shaohua ◽  
Bian Gang
Keyword(s):  
Data Processing ◽  
Real Time ◽  
Traditional Method ◽  
Correction Method ◽  
New Method ◽  
Determination Method ◽  
Error Correction Method ◽  
Compensation Error ◽  
Specific Determination ◽  
Processing Accuracy

The traditional method for processing multi-beam real-time attitude compensation data did not consider the influence of attitude compensation error, which left attitude residual in data. So a new method for processing multi-beam data of real-time attitude compensation was proposed. By studying the nature of attitude compensation error, the calculation method of systematic attitude compensation error was put forward. The concept of correction threshold was introduced and the specific determination method was given. Finally, combining with the principle of real-time attitude compensation, a systematic attitude compensation error correction method, which makes use of a tracking algorithm considering attitude to make secondary attitude correction, was proposed, and the specific processing flow was given. By comparing the data processing accuracy of the tradition method and the new method, the results showed that the new method can effectively reduce the influence of systematic attitude compensation error, and significantly improve the data processing accuracy.

scholarly journals Calculation of Pore Throat Radius Percentiles (25, 50 & 75) From Porosity and/or Permeability: Algyo Oil and Gas Field, Hungary

2021 ◽  
Vol 906 (1) ◽  
pp. 012004
Author(s):  
Nahla A. El Sayed ◽  
El sayed Abdel Moktader A.
Keyword(s):  
Size Distribution ◽  
Oil And Gas ◽  
Reservoir Characterization ◽  
Size Analysis ◽  
Pore Throat ◽  
Throat Radius ◽  
Gas Field ◽  
Reservoir Rocks ◽  
Oil And Gas Field ◽  
Porosity And Permeability

Abstract Pore throat size distribution of reservoir rocks has a great importance in hydrocarbon migration and entrapment. It is used for study permeability barriers, reservoir characterization and stratigraphic traps. In the present study 51 core samples obtained from Algyo oil and gas field were conducted to MICP laboratory technique to study pore throat size distribution. The inclusive graphical measures of gain size analysis were borrowed for pore throat size examination. Various pore throat radius percentiles such as 25,50 and 75 were calculated and related to both rock porosity and permeability. The obtained models were robust and reliable to use for pore throat radius percentiles (25,50 and 75) calculation. One of these models which is predicting the 50 percentiles was verified. It shows reliable coefficients of correlation (R2 = 0.77 and 0.79) as it is estimated from permeability and porosity, respectively.

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