Consecutive Dual Fracture Placement From One Location: Providing the Pinnacle Productivity From a Fracture Stimulated Wellbore

摘要

It is known that a fracture that is placed later in the life of a well will extend in a slightly different direction, mostly caused by the drainage of the fluid near the fracture face. In this situation, fracture redirection is most probably caused by the rapid pressure decline near the still-producing residual fracture face. Formation sharing between both fractures will not offer significant production increase. This paper, instead, discusses fracture redirection created by another fracture created in a near similar time domain. It is believed that the first fracture will cause a substantial short term effect on the stress field, and in fact, redirect to a near- perpendicular direction. Combined with the hard-to-accept concept that fractures generally shy away from highly productive areas, this approach will cause the second fracture to extend directly into a direction that makes intersection with such high productive areas to be commonplace; thus providing substantial production boost. In reality, the placement of a second fracture in the same wellbore in a similar locality and time span is quite difficult. The mouth of the fracture is generally unsupported, and therefore, the stress pattern at the wellbore face is generally returned to the pre-stimulation condition in a short time. Repressurization of the wellbore would then tend to reopen the first fracture. The hydrajet fracturing method is therefore proposed for placing the second fracture after a carefully precalculated (short) time delay, maximizing the temporary stress modification effect caused by the opening of the first fracture. The hydrajet technique will be used to exert the highest pressure at a location away from the wellbore and at an angular displacement of approximately 90 degrees from the first fracture, so that a new fracture can be initiated into a totally new direction. This can lead to a significant increase of revenue—cost ratio. In other words, a significant revenue increase can be obtained with just an incremental cost increase. Supporting simulation data are presented here.