海上高产气田防砂挡砂精度设计研究

摘要

Advanced high quality screen sand control is a commonly used sand control technology for high yield offshore gas ifeld, and the rationality of sand control precision design directly affects sand control effect. Currently, Because the sand standards of this kind gas ifeld is rare, the most popular design method of sand control precision is the Saucier’sD50=(5~6)d50 method which was proposed in the 1970s. And this method wasn’t suitable to some special formation due to simple consideration factors. This paper puts out an effective sand control standard which ifts the offshore gas ifeld perfect. Taking the actual formation cores in LiuHua 19-5 gas ifeld as example, the experiment of testing the effect of sand uniformity coefifcient on sand controlling precision design was conducted, and the results showed that a higher uniformity coefifcient may cause a lower accuracy of sand control. For the ifrst time the effect of sand clay content on the precision were studied, and another conclusion comes that the higher the clay content the greater the precision value and this phenomenon can be ignored if the clay content is not that high. We also found that the advanced high quality screen sand control should not be used if the clay content is higher than 14%. 8 × 8 set of sand simulation results followD50=(3~5)d50, which is different from the traditional method put forward by Saucier, and prove that the method of ifne sand control is reasonable for sandstone gas ifeld. All these conclusions can provide basis for sand control precision design in sandstone gas ifeld and sand control scheme optimization.%高级优质筛管防砂是海上高产气田常用的防砂工艺，挡砂精度设计的合理性直接影响防砂效果的好坏。由于缺乏该类气田的防砂标准，挡砂精度设计多按照70年代Saucier提出的D50=（5~6）d50设计原则，考虑因素单一，对于特殊地层不具备针对性。制定了海上高产气田的防砂有效标准，以流花气田19-5实际地层岩心为例，进行了均匀系数对挡砂精度设计影响规律实验，结果显示均匀系数越大最佳挡砂精度值越小。首次对泥质含量对气田挡砂精度设计影响规律进行了实验分析，结果显示泥质含量越高最佳挡砂精度值越大，但泥质含量较低时该影响可以忽略。实验结果还表明，当地层砂泥质含量高于14%时不宜采用高级优质筛管防砂。8×8组出砂模拟实验结果遵循D50=（3~5）d50，相对于传统的设计原则，实验佐证了海上高产气田精细防砂理念的正确性，为气田防砂挡砂精度设计和防砂方案优选提供了依据。