油田一体化生产系统产能评价方法

为了改进一体化生产系统的设计和管理,将守恒定律与多相流体模型、节流模型相结合,开发了用于评估一体化生产系统稳态条件下产能的数学模型和工作流程,通过求解数学模型来表征储集层、油井、油嘴、管汇、分离器一体化生产系统在稳定状态下的水力特征,将井数、油嘴尺寸和分离器压力视为可控变量,通过调控这些变量来优化某一时刻的一体化生产系统动态。研究发现:增加井数可以增大等效油管和等效管线的流量,但井数过高会使管汇压力升高,导致单井产量下降;增加油嘴尺寸可以提高一体化生产系统的产能;一体化生产系统的产量与分离器压力负相关,随着分离器压力的增加和油嘴尺寸的减小,井数增加带来的总产液量(一体化生产系统产能)增量将减少。现场实例验证结果显示,模型最大相对偏差为1.5%,证明了提出的数学模型和工作流程的正确性和有效性。

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.

Quantification of Reservoir Fluid Prediction Uncertainty Using AVO Fluid Inversion (AFI)

The AVO fluid inversion (AFI) technique was used to assess for fluids at the target levels of OPL-X in the deepwater Niger Delta, Nigeria. In this study, attempt is made to get a quantitative probability estimate of the possible reservoir fluids in both the shallow and deeper target levels. This was achieved through the development of a stochastic AVO model and an inversion to probability of different fluids using the Bayesian approach. AVO Fluid Inversion (AFI) technique provides a robust and inexpensive method for identifying potential hydrocarbon-filled reservoirs and provides a quantitative estimates of the uncertainties inherent in the prediction.

Coupled tripartite investigation of breaker fluid invasion and impact on hydrocarbon recovery in sandstone reservoirs

Breaker fluids are designed to dissolve filter cakes by breaking their long-chain molecules,thereby removing solid deposits on the wellbore wall.Although breaker fluids are not intended to infiltrate the hydrocarbon reservoir,they can invade and cause formation damage by altering sandstone reservoirs'wettability and relative permeability.This can lead to a reduction in the overall reservoir performance.This study coupled tripartite methods to investigate the potential impact of breaker invasion and transport in hydrocarbon reservoirs and its multiscale effect on the performances of sandstone reservoirs.We utilized experimental,analytical,and numerical methods to assess and predict the susceptibility of reservoirs to breaker fluid invasion and transportation.Our experimental and empirical investigations considered varying breaker fluid formulations to evaluate the effects of breaker fluid concentration,formation temperature,and solution gas-oil ratio(GOR)on residual-oil saturation(ROS)and oil-water relative permeability.By adopting the ROS and relative permeability associated with the 50%v/v breaker fluid mixture,the performance of the hydrocarbon reservoir was numerically simulated under the limiting scenarios of no-invasion,moderate-invasion,and deep-invasion of breaker fluid.The results indicate a positive correlation between breaker fluid concentration and ROS,highlighting the risks that breaker fluid invasion and deep infiltration pose to hydrocarbon recovery.Further,results show that both live-oil condition(LOC)and dead-oil condition(DOC)reservoirs are susceptible to the detrimental impacts of breaker fluid infiltration,while their invasion can reduce hydrocarbon recovery in both LOC(-6%)and DOC(-28%).The multi-scale effects on reservoir performance are more pronounced at near-wellbore and DOC than at far-field and LOC.Findings from this work provide valuable insights into the complexity of breaker-fluid invasion in sandstone reservoirs and the mitigation of associated risks to reservoir performance.