Influence factors and control of sand production in high-pressure fractured tight sandstone gas reservoirs: A case study on Dina 2 gas reservoir in the Tarim Basin

Dina 2 gas reservoir is a high-pressure fractured tight sandstone condensate gas reservoir, which is developed in the depletion mode. Continuous sand production is common in individual wells, which blocks wellbores and has severe impact on the normal production of the gas field. It is judged from the empirical sand production indicators that the possibility of sand production from matrix is low, and the current situation of sand production can be hardly resulted from the single factor of matrix. In this paper, the zones with lower rock compressive strength or higher effective overburden pressure were searched for from the point of rock mechanics, combined with the geological conditions and actual development situations in Dina. And accordingly, the factors influencing sand production were determined. It is indicated that the reduction of rock compressive strength is mainly caused by the low strength zones of conglomerate and conglomerate bearing layers, the weak zones of fault and fracture strength and the weak zones of perforation and acidification strength. The main reason for the increase of effective overburden pressure is the reduction of formation pressure. The closer it is to the bottom of perforation, the higher the effective overburden pressure of the rock is. The additional skin induced by contamination, afflux and stress sensitivity leads to the increase of production pressure difference. The larger the production pressure difference, the higher the effective overburden pressure near the wellbore is. It is discriminated according to Hoek-Brown strength criterion that some rocks can reach the breaking conditions under the joint effect of above factors. Finally, based on the cognitions, some sand control measures were proposed, such as optimizing perforation interval and orientation, increasing perforation density and penetration depth and adopting clean well completion technology. In addition, the sand control directions were pointed out, e.g. well location optimization and ceramic sand control.