Abstract
Well stimulation by hydraulic fracturing is one of the most unique of the commonly used oilfield practices. In spite of the fact that the treatments are relatively expensive and substantial permanent changes are induced in a fractured well, most of today's fracturing treatment applications are based on theoretical engineering relationships. For a treatment to be effectively ‘designed’, a myriad of treatment parameters must be considered using sophisticated fracture modeling software.
For those not experienced with fracturing, the development of a successful treatment approach may seem quite confusing. How does one know the ‘best’ or the ‘optimum’ fracturing treatment approach? Several related questions arise concerning candidate selection and methods to evaluate the effectiveness of the treatment.
The success of well stimulation by fracturing is readily observable through well response. Most often the response can be seen just hours after the treatment. Throughout its history, sufficient success has been achieved with fracturing that it has become one of the most widely used techniques for improving well productivity.
There are many instances where fracturing has not worked, or at least has not provided desired improvement in well productivity. Failure with fracturing always carries an economic impact whether it involves a single well or influences the feasibility of developing an entire field.
The purpose of this paper is not to provide an analytical treatise into all the reasons why fracturing treatments may fail. Rather, two approaches will be taken to address the topic "when fracturing doesn't work". The first will deal with the historical perspective and pertinent improvements in fracturing over the last 50 years will be discussed. Secondly, a series of common reasons for fracturing failures will be described. Finally, suggestions will be offered to provide further improvements in the success of application of hydraulic fracturing.