A new method to evaluate integrated production system capacity in oil fields

To improve the design and management of an integrated production system(IPS),a set of mathematical models and workflows are developed for evaluating the capacity of an IPS at steady-state conditions.Combining the conservation laws with applicable multiphase fluid and choke models,these mathematical models are solved to characterize the hydraulics of an integrated system of reservoir,wells,chokes,flowlines,and separator at steady state.The controllable variables such as well count,choke size and separator pressure are adjusted to optimize the performance of the IPs at a specific time.It is found that increasing the well count can increase the bulk flow rate of the production network,but too many wells may increase the manifold pressure,leading to decline of single-well production.Increasing the choke size can improve the capacity of the IPs.The production of the IPs is negatively correlated with the separator pressure.With increasing separator pressure and decreasing choke size,the increment of total fluid production(the capacity of IPS)induced by increasing well count decreases.Validation tests with field examples show a maximum absolute deviation is 1.5%,demonstrating the robustness and validity of the proposed mathematical models and workflows.

Tubing Dimension Optimization for the Development of an Offshore Gasfield

L1 is one of the largest offshore gas fields currently under development.In order to optimize the related design,nodal analysis is applied(including proper consideration of the plant productivity,sensitivity to the tubing size,erosion effects,liquid carrying performance,and tubing string).As a result of such approach,it is shown that 13Cr material should be chosen as the appropriate tubing material.Moreover,3-1/2 inches 9.3 lb/ft N80 tubing,4-1/2 inches 12.75 lb/ft N80 tubing,5-1/2 inches 17 lb/ft N80 tubing should be used for a gas production rate under 80×10^(4)m^(3)/d,between 80×10^(4)m^(3)/d and 120×10^(4)m^(3)/d and above 120×10^(4)m^(3)/d,respectively.

Combination Approach of FEM and Circuit System in IR Drop Analysis and Its Applications

A method was developed to solve the combined system of the current field and the circuit. The ＂super-node＂ was used to transform the matrix for conventional nodal analyses of a circuit system from non-positive definite to positive definite. Then, a positive definite matrix for the overall system was obtained by combining the matrix from the circuit nodal analysis method and the matrix resulted from finite element method （FEM） formulation to solve the FEM fields. This approach has been successfully applied to simulate the electrical potential and current distributions on each metal layer of printed circuit boards （PCBs） and integrated circuit （IC） packages for a given power supply. The simulation results can then be used to analyze the properties of the PCBs and IC packages such as the port resistances and IR drops. The results can also be used to optimize PCB and IC package designs, such as by adjusting the power/ground distribution networks.