Efficient development strategies for large ultra-deep structural gas fields in China

Li, Xizhe; Guo, Zhenhua; Hu, Yong; Luo, Ruilan; Su, Yunhe; Sun, Hedong; Liu, Xiaohua; Wan, Yong; Zhang, Yongzhong; Li, Lei

doi:10.1016/s1876-3804(18)30011-9

Cited by 52 publications

(17 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In order to verify the effect of the new method on the image processing of unconventional reservoir rocks, we carried out CT scanning to a tight sandstone core collected from a block of Changqing Oilfield. 39,40 The diameter of CT scanning sample is about 2.2 mm, the scanning resolution is 1.6 µm, and the measured porosity of the sandstone core is 0.086. At first, the CT scanning images are segmented by the two image segmentation methods, respectively.…”

Section: Figmentioning

confidence: 99%

A New Improved Threshold Segmentation Method for Scanning Images of Reservoir Rocks Considering Pore Fractal Characteristics

Lin

Yang

et al. 2018

Fractals

Self Cite

View full text Add to dashboard Cite

Based on the basic principle of the porosity method in image segmentation, considering the relationship between the porosity of the rocks and the fractal characteristics of the pore structures, a new improved image segmentation method was proposed, which uses the calculated porosity of the core images as a constraint to obtain the best threshold. The results of comparative analysis show that the porosity method can best segment images theoretically, but the actual segmentation effect is deviated from the real situation. Due to the existence of heterogeneity and isolated pores of cores, the porosity method that takes the experimental porosity of the whole core as the criterion cannot achieve the desired segmentation effect. On the contrary, the new improved method overcomes the shortcomings of the porosity method, and makes a more reasonable binary segmentation for the core grayscale images, which segments images based on the actual porosity of each image by calculated. Moreover, the image segmentation method based on the calculated porosity rather than the measured porosity also greatly saves manpower and material resources, especially for tight rocks.

show abstract

Section: Figmentioning

confidence: 99%

A New Improved Threshold Segmentation Method for Scanning Images of Reservoir Rocks Considering Pore Fractal Characteristics

Lin

Yang

et al. 2018

Fractals

Self Cite

View full text Add to dashboard Cite

show abstract

“…For gas reservoirs, the negative effect of water phase imbibition is more prominent; imbibition results in water intrusion at the edges and bottom of fractured gas reservoirs, while water phase trapping occurs in low-permeability tight gas reservoirs; these phenomena are important mechanisms that affect the recovery ratio of gas reservoirs. Along with the evolution of natural gas development technologies and hydraulic fracturing in recent years, the important role of water phase imbibition is more prominent in the water intrusion at the edges and bottom of fractured gas reservoirs and the exploration of tight gas and shale gas [5][6][7][8][9] . Therefore, the need for studies on the mechanism and theory of imbibition in oil and gas reservoirs is increasingly urgent [10][11][12][13] .…”

Section: Introductionmentioning

confidence: 99%

Microscopic Imbibition Characterization of Sandstone Reservoirs and Theoretical Model Optimization

Wan

et al. 2021

Preprint

Self Cite

View full text Add to dashboard Cite

Traditional porous media imbibition models deviate from the actual imbibition process in oil and gas reservoirs. Experimental studies on gas-water imbibition in reservoirs were carried out to describe the dynamic profile variation process of wet phase saturation in reservoirs and to further reveal the variation of the imbibition front and the imbibition amount. Optimization and correction methods were established, and experimental verifications were performed. Studies have shown the following: (1) Unlike homogeneous porous media, the water phase imbibition process in oil and gas reservoirs is more complicated, and it is impossible for the maximum saturation of imbibition to reach 100%. (2) Contrary to the theoretical hypothesis, the imbibition of water is not piston-like, and there is a clear transition zone at the imbibition front. This transition zone is the main cause of water saturation variations in the imbibition zone; with the expansion of the imbibition zone, the influence of the transition zone on water saturation weakens. (3) Traditional theoretical models predict a positive correlation between the imbibition amount and the measurements; however, there is a large deviation in the numerical values, which must be corrected. (4) The L-W model was optimized and the parameter group fluid factor and the reservoir factor were proposed to characterize the properties of the fluid and the reservoir, respectively. These two parameters have a clear physical significance and are easy to accurately test. After experimental correction, the parameters are favourably suitable for oil and gas reservoirs.

show abstract

“…The natural gas resources in China are rather abundant, and the gas reserves and production are increasing rapidly. According to the statistics from PetroChina Company Limited, China's natural gas geological resources have exceeded 220 trillion cubic meters in 2015, and the recoverable gas resources were about 31% of total resources, and the annual production increased from 17.4 billion cubic meters in 1995 to 135 billion cubic meters in 2015 with an average annual growth rate of 11% [2][3][4]. The Quaternary unconsolidated sandstone gas reservoir in the Qaidam Basin, Northwest China, is an important strategic successor gas source for the West-East Gas Pipeline project, which belongs to a rare biogenetic gas reservoir [5,6].…”

Section: Introductionmentioning

confidence: 99%

Study on the Water Invasion and Its Effect on the Production from Multilayer Unconsolidated Sandstone Gas Reservoirs

Shen

et al. 2021

Geofluids

Self Cite

View full text Add to dashboard Cite

Water invasion is a common occurrence in multilayer unconsolidated gas reservoirs, which results in excessive water production and reduces the economic life of gas wells. However, due to multiple layers, active edge water, and strong heterogeneity, the mechanism of water invasion and its effect in the unconsolidated sandstone gas reservoir require understanding in order to improve efficiency and minimize economic cost. In this study, an experimental study on edge water invasion of the multilayer commingled production in unconsolidated sandstone gas reservoirs was conducted to understand the water invasion process along with different permeability layers. The results show that the edge water invasion in the commingling production is mainly affected by two major factors including reservoir permeability and gas production rate, which jointly control the encroaching water advance path and speed. The nonuniform invade of edge water may occur easily and water prefers to invade toward the gas well along with high permeability layers when the commingling production is in the condition of large permeability gradient and high production rate. The bypass flow will occur when there are high permeability channels between the layers, which causes water blocking to low-permeability layers and periphery reservoirs far away from gas wells. The findings of this study can help for a better understanding of water invasion and the effects of reservoir properties so as to optimize extraction conditions and predict gas productivity in unconsolidated sandstone gas reservoirs.

show abstract

Efficient development strategies for large ultra-deep structural gas fields in China

Cited by 52 publications

References 5 publications

A New Improved Threshold Segmentation Method for Scanning Images of Reservoir Rocks Considering Pore Fractal Characteristics

A New Improved Threshold Segmentation Method for Scanning Images of Reservoir Rocks Considering Pore Fractal Characteristics

Microscopic Imbibition Characterization of Sandstone Reservoirs and Theoretical Model Optimization

Study on the Water Invasion and Its Effect on the Production from Multilayer Unconsolidated Sandstone Gas Reservoirs

Contact Info

Product

Resources

About