Research and practice of sidetracking schemes for complex wells in Bohai Oilfield

Abstract:

Sidetracking on the old well is one of the main means of stable and increase production in the Bohai Oilfield. There is an uncertainty of the cost for cleaning the well before sidetracking in complex wells. The formulation of reasonable sidetracking decision-making trees can effectively control the cost. This article sorts out the current status of the sidetracking design technology in Bohai Oilfield. In view of the problems in drilling design for complex wells such as sleeves and sieve pipes recycle， “falling fish” salvage and so on， based on the principle of “safety， economy， and efficiency”the sidetracing decision-making trees are formulated， such as the long-time casing recycle， the sieve pipes recycle or not， and the fish salvage or not. Taking the sidetracking design for 3 complex wells in Bohai Oilfield as an example， the application of the decision tree realizes the scientific design of the sidetracking solution. Compared with the conventional design method， it costs less than 15 million RMB. The decision tree proposed in this article has a certain promotion value.