深水浅层气田防砂方式优选及防砂参数优化

Optimization of Sand Control Methods and Parameters Selection for Shallow-Gas Fields in Deep-Water

为了解决深水气井开采过程中出砂程度高、防砂难度大的问题,研究了深水气井防砂优化设计技术。基于荔湾3-1深水浅层气田上覆岩层压力低、成岩性差、胶结强度低的特点,研制了一套可以进行深水气田大型防砂物理模拟的试验装置。该装置能够准确模拟深水气田储层特性条件下的常规裸眼优质筛管防砂与砾石充填防砂。采用物理试验与现场实际相结合的方法,对多种防砂方式及防砂参数进行了物理模拟,提出了适合深水气田提高产能的最佳防砂措施为"金属网优质筛管+裸眼砾石充填+适度扩眼增大砾石层厚度"。研究表明:气井防砂不同于油井的特殊性在于气体流速产生的携砂效应要明显大于增加砾石层厚度起到的挡砂效果,为保证深水气田出砂量小于10-9 m3/m3,砾石充填厚度应控制在60.96mm以内,以达到产能与出砂量的最优组合。

In order to solve problems such as high sand production and difficulties in sand control dur- ing the development of deep water gas wells, sand control design optimization for deepwater gas wells has been developed. Reservoirs in Liwan 3-1 Gas Field,the first deep water high yield gas field with low over- burden pressure, poor diagenesis and weak cementing strength. In view of these characteristics, a special large sand control physical modeling device was developed, then sand control design for deepwater gas field was optimized by using physical experiments and field data. The device is able to simulate conventional sand control with high quality screen or gravel packing under deepwater gas field conditions. Through a number of physical models of sand control mode and sand control parameters, the best sand control policy （wire netting screen＋gravel packing in open hole＋moderate ream to increase gravel thickness）was put forward to improve productivity. Studies show that the difference between sand control of gas well and oil well lies in the fact that sand carrying effect of gas is much higher than sand retention effect of gravel thickness increase. To achieve optimum productivity and sand production, gravel thickness should be con- trolled within 60. 96 mm to ensure sand production less than 0. 001 cubic meters.