Influences of Asphaltene Deposition on Rock/Fluid Properties of Low Permeability Carbonate Reservoirs

2001 ◽  
Author(s):  
Shedid A. Shedid
Keyword(s):  
Carbonate Reservoirs ◽  
Low Permeability ◽  
Asphaltene Deposition ◽  
Fluid Properties

A Novel Coreflood Test to Evaluate EOR Potential of Wettability-Altering Surfactants in Oil-Wet Heterogeneous Carbonate Reservoirs

2021 ◽  
Author(s):  
Yue Shi ◽  
Kishore Mohanty ◽  
Manmath Panda
Keyword(s):  
Oil Recovery ◽  
Carbonate Reservoirs ◽  
Wettability Alteration ◽  
Low Permeability ◽  
High Permeability ◽  
Matrix Permeability ◽  
Rock Heterogeneity ◽  
The Matrix ◽  
Flow Through ◽  
Main Factors

Abstract Oil-wetness and heterogeneity (i.e., existence of low and high permeability regions) are two main factors that result in low oil recovery by waterflood in carbonate reservoirs. The injected water is likely to flow through high permeability regions and bypass the oil in low permeability matrix. In this study, systematic coreflood tests were carried out in both "homogeneous" cores and "heterogeneous" cores. The heterogeneous coreflood test was proposed to model the heterogeneity of carbonate reservoirs, bypassing in low-permeability matrix during waterfloods, and dynamic imbibition of surfactant into the low-permeability matrix. The results of homogeneous coreflood tests showed that both secondary-waterflood and secondary-surfactant flood can achieve high oil recovery (>50%) from relatively homogenous cores. A shut-in phase after the surfactant injection resulted in an additional oil recovery, which suggests enough time should be allowed while using surfactants for wettability alteration. The core with a higher extent of heterogeneity produced lower oil recovery to waterflood in the coreflood tests. Final oil recovery from the matrix depends on matrix permeability as well as the rock heterogeneity. The results of heterogeneous coreflood tests showed that a slow surfactant injection (dynamic imbibition) can significantly improve the oil recovery if the oil-wet reservoir is not well-swept.

A Novel Deliverability Equation for Shallow Layer and Low Permeability Reservoirs with Horizontal Fracture

2012 ◽  
Vol 616-618 ◽  
pp. 1000-1007
Author(s):  
Yue Yang ◽  
Xiang Fang Li ◽  
Ke Liu Wu ◽  
Jian Yang ◽  
Jun Tai Shi ◽  
...  
Keyword(s):  
Low Permeability ◽  
Oil Viscosity ◽  
Reservoir Properties ◽  
Vertical Well ◽  
Horizontal Fracture ◽  
Vertical Permeability ◽  
Shallow Layer ◽  
Fluid Properties ◽  
Fracture Distribution ◽  
Low Permeability Reservoirs

In order to predict the productivity of vertical well for shallow layer and low permeability reservoirs with horizontal fracture, based on the theory of horizontal fracture distribution and oil seepage in reservoir, establish the reservoir seepage physical model for shallow layer and low permeability reservoirs with horizontal fracture, and derive a novel deliverability equation, considering the effect of reservoir properties, fluid properties, horizontal fracture parameters and working systems. Furthermore, the equation was applied and performed sensitivity analysis to the productivity of a vertical well in Yanchang Chang 6 layer reservoir. Results show that vertical permeability, oil viscosity and the semiminor axis of horizontal fracture have more significant impact on well productivity. With real cases, it is demonstrated the established deliverability equation is simple and practical and meets the engineering accuracy requirements.

Study on the Nonlinear Flow Percolation Law in Low Permeability Carbonate Reservoir of HF Oilfield

2014 ◽  
Vol 644-650 ◽  
pp. 5065-5070
Author(s):  
Shuai Jiang ◽  
Zheng Ming Yang ◽  
Xue Wei Liu ◽  
Meng Ting Wang ◽  
Qian Zhang
Keyword(s):  
Oil Industry ◽  
Carbonate Reservoir ◽  
Oil Field ◽  
Carbonate Reservoirs ◽  
Nonlinear Flow ◽  
Low Permeability ◽  
High Permeability ◽  
Threshold Pressure Gradient ◽  
Flow Situation ◽  
Low Permeability Reservoirs

With the development of the global oil industry,the production of the normal or high permeability reservoirs decline rapidly. Therefore, more and more low permeability reservoirs are used to the production stimulation. The oilfields overseas make great contribution to CNPC. The HF oilfield is one oilfield that the CNPC have in overseas. The HF oilfield is mainly the low permeability carbonate reservoirs which make it not easy to economically exploit. Due to the reason that the low permeability carbonate reservoirs present small porosity and the fluid’s flow situation in the low permeability carbonate reservoirs, the flow doesn't obey the Darcy's law. Thus it is greatly necessary to study the non-Darcy percolation characteristics. In this paper, the HF ‘s low permeability is tested and the threshold pressure gradient test is finished ,according to the experiment results, the nonlinear percolation ‘s law ,which is suited to HF-oil field , is illustrated and the reservoir classification is achieved.

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