关键词: 深层油藏, 压力衰竭, 水侵, 井周应力, 出砂压差

Abstract: Sand production prediction of deep ultra-high pressure horizontal wells is difficult and there are few targeted studies, so it is difficult to formulate reasonable and effective sand control measures, which has a great impact on oilfield production and economic benefits. With comprehensive consideration of the fluid flow in the wellbore, the stress change of wellbore rock under high temperature difference, fluid seepage effect, the complex distribution of in-situ stress on the wellbore, the formation pressure failure and the influence of water invasion on sand production, this paper establishes a sand production prediction model suitable for the critical pressure difference of sand production in deep high temperature and high pressure wells in the southern margin. The analysis shows that high drawdown is the dominant factor; the temperature difference between the wellbore and the formation caused by high production will produce stress in the wellbore and affect the stability of the wellbore; in the later stage of production, the decrease of formation pore pressure will increase the circumferential stress of wellbore, and the invasion of formation water will reduce the rock strength, both of which will increase the risk of sand production. The results of sand production differential pressure verification by using the example well in the southern margin are consistent, which can provide guidance and reference for the prediction of sand production critical differential pressure of similar deep high temperature and high pressure wells and the formulation of reasonable production differential pressure.

Key words: deep reservoir, pressure depletion, water intrusion, circumferential stress, sand production differential pressure