Study On The Technology Of Intercommunicating The Relief Well And The Accident Well

While drilling at sea and on land, when the oil-gas wells are on fire or occurring blowout and oil spills and other accidents, relief well is the last but most effective means to deal with such incidents. In terms of connectivity technologies of the relief well and the accident well, many foreign scholars have done some related researches, but in China it’s a shortage on the relief well technology, and research in this area is fewer, so searching in this technology has a very important significance.This paper analyzes various factors that lead to errors during drilling directional wells and gives six major sources of systematic error, and on this basis, gives the individual measurement error into the wellbore position uncertainty method and then creates a directional wellbore position uncertainty error ellipsoids model and it’s calculation method, then provide a method to calculate the borehole position relative uncertainty of error ellipsoid between the relief well and the accident well. Then it gives the method to find the real accident well bottom which is used to calculate the intercommunication point’s error ellipsoid.This article divides the intercommunicating way of the relief well and the accident well into two main ways which are the intercepting way and the fracturing way, and establishes the related models of the two intercommunication methods. And then provides a tracking design method for when using a relief well to intercept with the accident well and finds the kill points which flow parameters such as depth and flux. And then established the theory of whether the fracture could meet the requirement to dynamic kill an accident well. And then gives the method of discriminating if the communication was established. Finally, an example relief 69-11 group was provided to verify the correctness of the model established before. It’s a guidance for the relief well design and drilling.