In order to find an accurate brittleness and stiffness for a rock, Rickman et al. (Rickman) has come up with a method that has been used frequently. In order to determine the brittleness index of a certain section of rock, Rickman advises the use of two rock parameters: Poisson’s ratio and Young’s modulus (Rickman). The ideal brittleness is a low Poisson’s ratio and a high Young’s modulus. A low Poisson’s ratio indicates the rocks capability to fracture when stress is applied and a high Young’s modulus indicates the rocks stiffness for the fracture to stay open when the proponent is in place. This can be seen in Figure 1 below.
The limitations of the Rickman’s model include not incorporate other rock parameters that determine the brittleness …show more content…
That is for ideal cases, on directional flow. However in the real world that is not the case, it is much more arduous. The Darcy’s equation is still used because it gives physical limits to the production rate and helps understanding how the flow rate is affected by different parameters (Lund). Additionally, in order for fluid to flow there has to be a pressure gradient. As this pressure gradient increases the fluid flow rate increases as well. The Darcy equation incorporates pressure gradient by a negative sign in the equation. The negative sign indicates that fluid in a high pressure area will flow to an area of low pressure. Pressures are related to extracting hydrocarbon from a reservoir. As hydrocarbons are being extracted, the pressure gradient decreases. The pressure gradient will eventually decrease to a point where there won’t be any more pressure to maintain the flow of the fluid. At this point, injection wells would be utilized to increase the pressure by injecting water and gas (Lund). Besides pressure determining how fast the fluid will flow, there are other factors to consider such as permeability, permeability direction, and viscosity. A higher permeable reservoir needs less pressure to match the flow rate of a low permeable reservoir. Also the direction of permeability is important, either vertical or horizontal. Normally horizontal has greater …show more content…
This method fits a curved line to the production data. Depending on the decline curve of the production, the future production can be estimated. The reason this method is commonly used, it does not need to be a vast amount of data to produce the decline curves. There can be a small amount of data and the curve can be generated. However, there are some negatives about this method such as the future production estimates. They are dependent on the decline curve. Thus, having one decline curve for a whole field could result in error. Production can differ greatly with in the field. This has to be kept in mind when producing decline
The limitations of the Rickman’s model include not incorporate other rock parameters that determine the brittleness …show more content…
That is for ideal cases, on directional flow. However in the real world that is not the case, it is much more arduous. The Darcy’s equation is still used because it gives physical limits to the production rate and helps understanding how the flow rate is affected by different parameters (Lund). Additionally, in order for fluid to flow there has to be a pressure gradient. As this pressure gradient increases the fluid flow rate increases as well. The Darcy equation incorporates pressure gradient by a negative sign in the equation. The negative sign indicates that fluid in a high pressure area will flow to an area of low pressure. Pressures are related to extracting hydrocarbon from a reservoir. As hydrocarbons are being extracted, the pressure gradient decreases. The pressure gradient will eventually decrease to a point where there won’t be any more pressure to maintain the flow of the fluid. At this point, injection wells would be utilized to increase the pressure by injecting water and gas (Lund). Besides pressure determining how fast the fluid will flow, there are other factors to consider such as permeability, permeability direction, and viscosity. A higher permeable reservoir needs less pressure to match the flow rate of a low permeable reservoir. Also the direction of permeability is important, either vertical or horizontal. Normally horizontal has greater …show more content…
This method fits a curved line to the production data. Depending on the decline curve of the production, the future production can be estimated. The reason this method is commonly used, it does not need to be a vast amount of data to produce the decline curves. There can be a small amount of data and the curve can be generated. However, there are some negatives about this method such as the future production estimates. They are dependent on the decline curve. Thus, having one decline curve for a whole field could result in error. Production can differ greatly with in the field. This has to be kept in mind when producing decline