The influence of fine particles composition on optimal design of sand control in offshore oilfield

摘要

The fine particles have significant influence for sand control mode selection. According to investigation and analysis, we learn that the gravel packing has been used widespread in sand control when the contents of fine particles are high. Based on designing the pre-packed screen, different fine particles sand control research is completed combining with test method. (1) We find that the sequence of fine particles flowing into the well has an enormous impact on the screen jam rate, and the smaller the fine particle diameter, the more obvious the screen plugging. The jam rate for the pure clay is five times with pure fine-silty sand, and four times with mixture of the fine-silty sand and the clay. When the experimental achieve octet stability, the Fluid Productivity Index Per-Meter (FPIPM) of the pure clay is pretty much equivalent with the mixture of the fine-silty sand and the clay. It is 70?% of the pure fine-silty sand FPIPM but has limited influence to effectiveness of the blockage. (2) Sand control selection in the offshore oilfield suggests the gravel packing will be applied when the fine particles content is over 5?%. Compared to this select range, it is conservative and experiments show that the fine particles content achieves 100?%, the pre-packed screen also can cope with sand control effectively. When comparing with experimental result about the gravel packing sand control under the same condition, the both FPIPM in steady is same. So, it is more suitable to be widely used combined with the production cost.