Changes

 

 

 

RESERVOIR rock have many lithologies like sandstones, limestones, granitic, tuff, and shale. Reservoir filled by hydrocarbon on fracture or pores. All reservoir hydrocarbon content connate water . some reservoir content connate water in the micropore that content 10-60% from the pores volume.

Reservoir rock have many lithologies like sandstones, limestones, granitic, tuff, and shale. Reservoir filled by hydrocarbon on fracture or pores. All reservoir hydrocarbon content connate water . some reservoir content connate water in the micropore that content 10-60% from the pores volume.

Information about scale factor needed to conceptualized reservoir.  Scale factor can differences by microscopic; relates to pores and sand grains, macroscopic; relates to conventional core-plug scale, megascopic relates to the scale of grid-blocks in simulation models, and gigascopic relates to regional scale.  

Information about scale factor needed to conceptualized reservoir.  Scale factor can differences by microscopic; relates to pores and sand grains, macroscopic; relates to conventional core-plug scale, megascopic relates to the scale of grid-blocks in simulation models, and gigascopic relates to regional scale.  

==Physical Properties of Reservoir==

==Physical Properties of Reservoir==

 

===Homogeneity and Heterogeneity===

===<big>Homogeneity and Heterogeneity</big><big></big>===

Homogeneity factor consist uniform material. Homogeneity factor is similar depositional environment, grain distribution is relatively similar, and similar kind of intensity diagenesa. While the heterogeneity factors is changes in depositional environment, sedimentary material, grain size distribution, and facies, also different type and intensity of diagenesis processes.  

Homogeneity factor consist uniform material. Homogeneity factor is similar depositional environment, grain distribution is relatively similar, and similar kind of intensity diagenesa. While the heterogeneity factors is changes in depositional environment, sedimentary material, grain size distribution, and facies, also different type and intensity of diagenesis processes.  

 

===Pore Structure and Geometry===

===<big>Pore Structure and Geometry</big><big></big>===

 

Pore structure varies with the size, shape, and composition of natural grains, as well as fractures. Geometry ranging from <1 micron to 100 micron . Pore characteristic will determine oil recovery method.

Pore structure varies with the size, shape, and composition of natural grains, as well as fractures. Geometry ranging from <1 micron to 100 micron . Pore characteristic will determine oil recovery method.

 

===Reservoir Pressure===

===<big>Reservoir Pressure</big><big></big>===

 

Fluid in reservoir have hydrostatic pressure that associated reservoir system. Pressure from overburden rock also press the pore and increase the fluid pressure.  

Fluid in reservoir have hydrostatic pressure that associated reservoir system. Pressure from overburden rock also press the pore and increase the fluid pressure.  

 

===Temperature Reservoir===

===<big>Temperature Reservoir</big><big></big>===

 

Temperature at some depth comes from gradient geothermal  and it is directly proportional to the depth.

Temperature at some depth comes from gradient geothermal  and it is directly proportional to the depth.

Reservoir bounded by impermeable layers and fluid contact. Field boundaries is ensured through the well but based on well data; electric logs,  well flow testing, and repeat formation tester (RFT). Boundary of water and hydrocarbon zones is reduced gradually. This saturation interval resulted in the transition zone.  This zone is used as perforation zone in production well.

Reservoir bounded by impermeable layers and fluid contact. Field boundaries is ensured through the well but based on well data; electric logs,  well flow testing, and repeat formation tester (RFT). Boundary of water and hydrocarbon zones is reduced gradually. This saturation interval resulted in the transition zone.  This zone is used as perforation zone in production well.

==Physical Properties of Rocks==

==Physical Properties of Rocks==

Porosity (Phi) 5, permeability (k) mD, fluid saturation (S) %, capiler pressure (Pc) Psi, compressibility (C) Psi^-1, resistivity (R) ohm.   

Porosity (Phi) 5, permeability (k) mD, fluid saturation (S) %, capiler pressure (Pc) Psi, compressibility (C) Psi^-1, resistivity (R) ohm.   

 

===Porosity===

===<big>Porosity</big><big></big>===

Porosity is the amount of free space compared to the bulk volume of rock. Porosity affects the ability of the rock to keep the fluid inside the pores of the rock. The pores can be interconnected and isolated. The pores are interconnected referred to as the effective porosity. Total porosity of rock is a combination of pore volume and pore volume isolated interconnected. While porosity very small called microporosity. Connate water is stored in this microporosity.

Porosity is the amount of free space compared to the bulk volume of rock. Porosity affects the ability of the rock to keep the fluid inside the pores of the rock. The pores can be interconnected and isolated. The pores are interconnected referred to as the effective porosity. Total porosity of rock is a combination of pore volume and pore volume isolated interconnected. While porosity very small called microporosity. Connate water is stored in this microporosity.

# Formula for absolute porosity

# Formula for absolute porosity

                <math>\phi_\text{ab} = \frac{\text{Volume of total pores}}{\text{Total rocks volume}}</math>

#* <math>\phi_\text{ab} = \frac{\text{Volume of total pores}}{\text{Total rocks volume}}</math>

#* <math>\phi_\text{eff} = \frac{\text{Volume of interconnected pores}}{\text{Total volume of rocks}}</math>

[[File:Pore distribution.png|300px|thumbnail|Figure 1.Pore distribution inside the reservoir rocks]]

[[File:Pore distribution.png|600px|thumbnail|center|Figur 1.Pore distribution inside the reservoir rocks]]

===<big>Permeability</big><big></big>===

===Permeability===

Permeability is the ability of the rock to drain fluid (hydraulic conductivity) through the pores of the rock. The bigger the pore throat more easily drain the fluid. Unit permeability is miliDarcy.

Permeability is the ability of the rock to drain fluid (hydraulic conductivity) through the pores of the rock. The bigger the pore throat more easily drain the fluid. Unit permeability is miliDarcy.

# Absolute permeability (Ka)

====Absolute permeability (Ka)====

Absolute permeability retrieved from conventional core analysis or by the approach through equations based on log analysis. Empirical equation that can be used is :

Absolute permeability retrieved from conventional core analysis or by the approach through equations based on log analysis. Empirical equation that can be used is :