Abstract:
The current reference temperature resistance capacity for sand control screen liner selection of thermal recovery wells in Bohai Oilfield did not take account the influence of well conditions.Consequently,there was a breakdown of selected sand control screen liner in some thermal recovery wells because they failed to meet the requirements of heat injection.To solve the problem,researchers developed a numerical simulation method for calculating screen liner temperature resistance ability in thermal horizontal wells by means of the mechanical analysis of sand control screen liner in heat injecting conditions.Further,they considered the impact of bending and thermal stress on screen liner failure.Using this method,the temperature resistance capacity of sand control screen liner in six thermal recovery horizontal wells in Bohai Oilfield was calculated.Next,the reduction range of temperature resistance capacity of three types of sand control screen liner,i.e.star mesh,metal mesh and bridge-type composite under unit dog leg severity was analyzed.The results showed that the temperature resistance calculated under the bending stress was in good agreement with the actual situation.In fact,the temperature resistance of three types of sand control screen liner under unit dog leg severity was reduced by 6-16℃.Further,the reduction range of temperature resistance of sand control screen liner under unit dog leg severity increased with sand control screen line size.The higher steel grade of sand control screen liner generated a more limited range of reduced temperature resistance,and the influence of the degree of steel grade was greater than that of screen liner size.The grade TP110H,BG110H metal mesh or bridge-type composite sand control screen liner had high temperature resistance and could meet the heat injection requirements of thermal recovery wells in Bohai Oilfield.Therefore,we could conclude that the effect of bending stress on the temperature resistance capacity of sand control screen liner should be taken into account for selecting sand control screen liner for thermal recovery of heavy oil in horizontal wells.Notably,failing to consider it might cause the failure of sand control,and further affect the development effect of heavy oil thermal recovery.