裂缝性地层漏失模拟试验研究

Simulation Experiment on Lost Circulation Control for Fractured Formation

裂缝性地层在油气田中普遍发育,由此导致漏失现象也经常发生,如何有效模拟裂缝性地层漏失是个普遍性难题。采用粒径3～5cm具有一定高度的砾石层来模拟地下裂缝性地层;试验结果表明,砾石层可以有效模拟1～2cm的裂缝。同时,利用该方法评价并优选了裂缝性地层堵漏材料,认为单一的刚性材料、纤维材料或片状材料对于裂缝性地层堵漏效果均不理想,刚性材料和纤维状材料以及片状材料复合堵漏效果比较明显。3%粗粒石灰石+3%核桃壳+3%锯末+1%云母,对1～2cm裂缝可以有效堵漏。

Fractured formation was widely developed in oil and gas fields,thus lost circulation was often occurred.It was difficult to simulate lost circulation in fractured formation.Gravel bed with diameter of 3～5cm was used to simulate the lost circulation.Results show that gravel bed can simulate 1～2cm fractures effectively.Lost circulation materials were optimized by using the gravel bed method.It was considered that unique rigid materials,fibrous materials or flake materials were not ideal for using in fractures.The effect of the composite materials was obvious for Lost circulation control.The formula of 3% coarse limestone particle+3% walnut shell+3% sawdust+1% mica can be effectively used for lost circulation control.