The Ledong-30 area is located in the southern part of the central depression of the Yinggehai basin, where the exploration activity aims to gas in the middle and deep strata is started lately. The previous studies on ...The Ledong-30 area is located in the southern part of the central depression of the Yinggehai basin, where the exploration activity aims to gas in the middle and deep strata is started lately. The previous studies on the sedimentary system and main controlling factors of reservoir formation are mainly focused on the middle and shallow strata above the Huangliu Formation. Based on a fine interpretation of seismic data, the sedimentary characteristics, internal structures, and distribution rules of submarine fans and gravity flow channels in the Ledong-30 area are analyzed in this paper. In addition, the dynamic migration processes of their planar distribution and the vertical evolution law (vertical sequence combinations and superposition features of turbidity events) are also addressed. At last, the internal structural characteristics of the gravity flow system and comprehensive formation mechanisms of the large-scale gravity flow sediments (turbidities fans) are also been analyzed, which is helpful for the prediction of favorable reservoir distribution. The results can be used directly to guide oil and gas exploration in the Ledong area of the Yinggehai basin.展开更多
Stress sensitivity is a key factor affecting the productivity of single wells in low permeability gas reservoirs. A well test model for heterogeneous composite gas reservoirs under the influence of stress-sensitive ef...Stress sensitivity is a key factor affecting the productivity of single wells in low permeability gas reservoirs. A well test model for heterogeneous composite gas reservoirs under the influence of stress-sensitive effects was established. Based on the theoretical model, the well test was designed by gradually increasing the pressure difference. The relationship between abnormal high pressure and reservoir stress sensitivity was analyzed. Theoretical research shows that stress sensitivity will cause permeability damage during the production process, and the pressure drop test curve shows that the physical properties of the reservoir have gradually deteriorated. The pressure recovery test curve shows that the physical properties of the reservoir are getting better. Field practice shows that stress sensitivity is related to the formation of abnormally high pressure in the formation without considering the micro-cracks in the formation. Stress-sensitive reservoirs are generally unbalanced and compacted due to overpressure, for fluid expansion/conduction overpressure in Ledong Area. For these reservoirs, there is almost no stress sensitivity. The research results have significance for guiding the design and data interpretation of stress-sensitive reservoir.展开更多
文摘The Ledong-30 area is located in the southern part of the central depression of the Yinggehai basin, where the exploration activity aims to gas in the middle and deep strata is started lately. The previous studies on the sedimentary system and main controlling factors of reservoir formation are mainly focused on the middle and shallow strata above the Huangliu Formation. Based on a fine interpretation of seismic data, the sedimentary characteristics, internal structures, and distribution rules of submarine fans and gravity flow channels in the Ledong-30 area are analyzed in this paper. In addition, the dynamic migration processes of their planar distribution and the vertical evolution law (vertical sequence combinations and superposition features of turbidity events) are also addressed. At last, the internal structural characteristics of the gravity flow system and comprehensive formation mechanisms of the large-scale gravity flow sediments (turbidities fans) are also been analyzed, which is helpful for the prediction of favorable reservoir distribution. The results can be used directly to guide oil and gas exploration in the Ledong area of the Yinggehai basin.
文摘Stress sensitivity is a key factor affecting the productivity of single wells in low permeability gas reservoirs. A well test model for heterogeneous composite gas reservoirs under the influence of stress-sensitive effects was established. Based on the theoretical model, the well test was designed by gradually increasing the pressure difference. The relationship between abnormal high pressure and reservoir stress sensitivity was analyzed. Theoretical research shows that stress sensitivity will cause permeability damage during the production process, and the pressure drop test curve shows that the physical properties of the reservoir have gradually deteriorated. The pressure recovery test curve shows that the physical properties of the reservoir are getting better. Field practice shows that stress sensitivity is related to the formation of abnormally high pressure in the formation without considering the micro-cracks in the formation. Stress-sensitive reservoirs are generally unbalanced and compacted due to overpressure, for fluid expansion/conduction overpressure in Ledong Area. For these reservoirs, there is almost no stress sensitivity. The research results have significance for guiding the design and data interpretation of stress-sensitive reservoir.
