Luger and Hergarden proposed the first rational method for predicting the maximum allowablepressure before hydraulic fracturing during HDD installation at the 1988 International No-Dig Conference inWashington D.C. In some respects, the industry has come a long way since the development of this model and, inothers, nothing has changed. Some HDD projects are still designed and constructed without a rational evaluation ofhydrofracture risks, or the evaluation is conducted without understanding the significance and relevance of modelassumptions and input parameters.Incorporating information from the oil well drilling and trenchless technology industries, this paper presents ahistorical summary and review of practices and recommendations for evaluating the risk of hydrofracture duringHDD. By understanding the history and components of the cavity expansion and annular flow modeling equations,the equations can be applied more accurately and with better results. The desired results are better understanding ofhydrofracture risks and better risk management during design and construction.
展开▼
