Different core analyses on samples from oil and gas wells have shown, that a combination of core relaxation measurements (ASR) and the investigation of wave velocity anisotropy (WVA) has led to reliable results in determining in situ state of rock stress.

Further aspects concern the dimension and stability of boreholes. Knowing the stress data and different rock mechanical parameters, a risk-analysis for openhole stability and completion can be worked out.

Any fracturing process is controlled by the in situ stress. In preparing multi-fracturing treatment strategies, the information about the 3D-state

of in situ stress is a need, to develop 3D-fracture propagation models. The rock stress is an important parameter for optimal exploitation of gas and oil reservoirs. Investigations of openhole instabilities (breakouts, convergence) can be performed for already existing boreholes in the frame of a back-analysis (analysis of damage). The stability of horizontal wells depends on the direction of the bore path and the orientation of the 3D-stress distribution, respectively.

Generally, there is a close relationship between the wellbore stability, the wellbore deviation and the local rock stress regime.

If there is any planning of a coring program, it is recommendable to take into account a core-based analyzing program including the determination of rock stresses. When a borehole is cored one should get as much information as possible from the cores. A core analyzing program concerning rock stresses delivers information not only essential for prediction of fracture propagation, but also useful for decisions of openhole completions.

DCM offers a valuable service to minimize exploration problems.