The problem of increasing of reliability of pipeline transportation is one of the most actual problems in petroleum industry.There are special difficulties related to reliability maintenance of pipelines operated in difficult environmental conditions.Some problems have been solved: statistical comparison of the maximum deflections of pipeline spans in the conditions of restraining by real ground and position in anchorage.Also the model of interaction of the pipeline and a ground has been investigated.It represents reaction of a nonlinear spring.During the statistical analysis it has been revealed that values of span deflections under both conditions (restraining in ground and position in anchorage) depend on many parameters: working pressure, diameter, wall thickness and steel mark.And relation of the maximal deflections under these two conditions exponentially depends only on type of a ground and spans length;and remains constant with any internal parameters of the pipeline.This dependence can be established analytically by means of interpolation by a method of the least squares.As a result special coefficient has been received.It allows us to define a pipeline span deflection in the conditions of restraining in real ground if we know the pipeline span deflection in position in anchorage.It will essentially simplify process of calculation of pipeline which is in areas of karstic formations, in washed out grounds and calculations during digging of tranches during repair work.As it demonstrates that if some values depend on set of factors, relations of these values may depend on only one factor.This research contains analysis, calculations, new formula.The conclusion that the new formula is useful is made.This method has been successfully used for detection of potential "black spots" of oil pipelines in Kazakhstan.Application of this method lets us save calculation time with remain of required calculation accuracy.