| 摘要 |
<p>The invention is for use in the oil and gas extraction industry. The aim is to enhance the efficiency of working terrigenous argillaceous strata. The novelty lies in the fact that the fluid used in working the stratum is activated before use. In order to prevent swelling and peptization of the clay particles (through the formation of bonds between them) certain reagents such as K?+ and Al3+¿ are added to the solution. To improve flushing, a saturated solution of sodium bicarbonate, activated by saturation with a gas such as carbon dioxide, is used. The working of the stratum is best carried out at the same time as the pressure in the well is relieved through slit apertures, using the operating fluid as the pressure medium. A further reduction in the mechanical stresses in the critical zone is achieved by creating a further pair of vertical slits configured symmetrically about the axis of the well, the said second pair being perpendicular to the first and the depth of the slits in the second pair being between 0.2 - 0.5 that of the slits in the first pair.</p> |
