论文部分内容阅读
方法采用常规三轴岩石强度试验装置，进行井下温度压力条件下的泥浆侵入过程模拟试验。目的观察不同泥浆密度条件下井下天然裂缝的开闭状态、张开度及泥浆侵入裂缝的过程和深度。结果随着泥浆密度的增加，裂缝张开的最大距离和张开的区域减小，当泥浆密度达到临界值时，节理完全闭合，继续增大泥浆密度，裂缝张开的最大距离和张开的区域也增大。当裂缝有充填物时，随泥浆柱压力增加，泥浆侵入深度增大，当泥浆柱压力超过第一临界值后，侵入深度急剧增大。结论在条件允许的情况下，应尽量降低泥浆密度，使力学损害降至最低。泥浆柱压差应小于 １０ ＭＰａ，以使泥浆侵入深度控制在较小范围内，减小油气层损害。
Methods The conventional triaxial rock strength test equipment was used to simulate the mud invasion process under the temperature and pressure conditions in the well. Objective To observe the opening and closing of natural fractures under different mud densities, the opening degree and the process and depth of mud invasion into fractures. Results As the mud density increased, the maximum distance of crack opening and the open area decreased. When the mud density reached the critical value, the joints closed completely and the mud density, the maximum distance of crack opening and the open The area also increased. When the crack is filled, the invasion depth increases with the increase of the pressure of the mud column. When the pressure of the mud column exceeds the first critical value, the penetration depth increases sharply. CONCLUSIONS Where conditions allow, mud density should be minimized to minimize mechanical damage. The pressure difference of the mud column should be less than 10 MPa, so that the mud invasion depth can be controlled within a smaller range and the damage of the oil and gas layer can be reduced.