On the Mechanisms of the Formation of Zones with Abnormally High Rock Pressure and Methods for Predicting them in Undeveloped Rock Systems

摘要

To the list of the most serious and uncontrolled geological complications arising during the drilling of wells,it is well known the Oil,Gas and Water Shows(OGWS)which often happens in areas with formed waterflooding zones.Risks result from the lack of the ability to predict the location of Abnormally High Reservoir Pressures zones(AHRPZ)due to high uncertainties in the movement of the injected fluid in formation.Oversight of the meeting of reservoir zones with high reservoir pressure is conducted on the basis of a number of analytical tasks: making water-oil factor maps,ping the front of the injection water in formation,pressure(isobar)maps,drilling history,special field geophysical tests for formation cross-flows,CO-logs across not perforated productive intervals.However,by using the classical development tools,it is possible to solve the issues with predicting the potential high pressure zones in the flooded reservoirs,but how we can predict the abnormal pressure systems in reservoirs that are not under development and carry exclusively technogenic genesis?! In this paper we will talk about the forecasting possibility of the abnormal pressures in the transit reservoir systems using the example of the Priobskoye oilfield.Those systems are not involved in the development process either because of the lack of hydrocarbon reserves or because of the absence of the reservoir at all.The authors hope that this materials allow to describe the tools that will protect other colleagues from complications related with well drilling and their re-drilling with associated material costs.