涩北气田气井合理配产的综合技术对策

An integrated technical strategy on well production allocation in the Sebei gas field

柴达木盆地涩北气田具有岩性疏松易出砂、多层、气水关系复杂易出水、储量动用程度不均衡等开发技术难题,为了确保气田的稳产及合理高效开发,在制订开发技术对策时单井的合理配产非常关键。针对该气田气井出水、储层岩性疏松应力敏感及多层合采等特点,常规的气藏气井配产方法已不适用,从出水气井无阻流量的评价、抑制地层出砂的临界产量计算、多层多气水系统抑制边水推进的平衡采气等角度出发,探讨了涩北气田气井合理配产的综合技术对策。运用气藏数值模拟技术,对涩北一号气田典型层组的合理配产方案进行了开采指标预测,模拟结果显示所提出的以动态配产为技术特点的配产策略能够达到稳气控水、最大限度地提高天然气采出程度的目的。

The Sebei gas field of Qaidam basin is characterized by loose sandstone,multi-layer,and complex gas-water contacts,so many technical problems in the exploitation of this gas field including sanding,water breakthrough,and unbalanced reserves producing level in each layer are not easy to be handled.To ensure this gas field to be developed with steady gas recovery in a reasonable and high efficient way,it is essential for gas field managers to make a proper plan on each single well production allocation while deciding on the development strategy.The conventional gas well allocation policy is obviously not applicable to this situation in terms of such peculiarities as breakthrough,stress sensitivity of loose sandstone reservoir,and the commingled gas production,so an integrated strategy on well production allocation in the Sebei gas field was discussed in detail in many aspects including the evaluation method of AOF production of a gas well with water breakthrough,the calculation of the sanding critical production rate,and the gas recovery adjustments to balance the movement of gas-water front in each layer.By use of numerical simulation on gas reservoirs,a case study was conducted in a typical layer of the Sebei-1 gas field on the reasonable well production allocation strategy.The simulation results show that this proposed strategy can achieve maximum gas recovery with a steady production rate and keep the producing water under control.