Determination of In-Situ Stresses From Hydraulically Fractured Spherical Cavities

1983 ◽  
Vol 105 (2) ◽  
pp. 125-127 ◽  
Author(s):  
W. E. Warren

Several problems in analysis can arise in estimating in-situ stresses from standard hydraulic fracturing operations if the borehole is not aligned with one of the principal stress directions. In these nonaligned situations, the possibility of fracturing a spherical cavity for estimating the in-situ stresses is investigated. The theory utilizes all the advantages of direct stress measurements associated with hydraulic fracturing and eliminates the geometrical problems associated with the analysis of hydraulic fractures in cylindrical boreholes.

2015 ◽  
Author(s):  
Manhal Sirat ◽  
Mujahed Ahmed ◽  
Xing Zhang

Abstract In-situ stress state plays an important role in controlling fracture growth and containment in hydraulic fracturing managements. It is evident that the mechanical properties, existing stress regime and the natural fracture network of its reservoir rocks and the surrounding formations mainly control the geometry, size and containments of produced hydraulic fractures. Furthermore, the three principal in situ stresses' axes swap directions and magnitudes at different depths giving rise to identifying different mechanical bedrocks with corresponding stress regimes at different depths. Hence predicting the hydro-fractures can be theoretically achieved once all the above data are available. This is particularly difficult in unconventional and tight carbonate reservoirs, where heterogeneity and highly stress variation, in terms of magnitude and orientation, are expected. To optimize the field development plan (FDP) of a tight carbonate gas reservoir in Abu Dhabi, 1D Mechanical Earth Models (MEMs), involving generating the three principal in-situ stresses' profiles and mechanical property characterization with depth, have been constructed for four vertical wells. The results reveal the swap of stress magnitudes at different mechanical layers, which controls the dimension and orientation of the produced hydro-fractures. Predicted containment of the Hydro-fractures within the specific zones is likely with inevitable high uncertainty when the stress contrast between Sv, SHmax with Shmin respectively as well as Young's modulus and Poisson's Ratio variations cannot be estimated accurately. The uncertainty associated with this analysis is mainly related to the lacking of the calibration of the stress profiles of the 1D MEMs with minifrac and/or XLOT data, and both mechanical and elastic properties with rock mechanic testing results. This study investigates the uncertainty in predicting hydraulic fracture containment due to lacking such calibration, which highlights that a complete suite of data, including calibration of 1D MEMs, is crucial in hydraulic fracture treatment.


Author(s):  
J. P. Sarda ◽  
P. J. Perreau ◽  
M. Bouteca ◽  
P. Charlez ◽  
J. L. Detienne

1972 ◽  
Vol 98 (1) ◽  
pp. 169-169
Author(s):  
Merlin D. Copen ◽  
George B. Wallace

2006 ◽  
Vol 306-308 ◽  
pp. 1509-1514 ◽  
Author(s):  
Jing Feng ◽  
Qian Sheng ◽  
Chao Wen Luo ◽  
Jing Zeng

It is very important to study the pristine stress field in Civil, Mining, Petroleum engineering as well as in Geology, Geophysics, and Seismology. There are various methods of determination of in-situ stress in rock mass. However, hydraulic fracturing techniques is the most convenient method to determine and interpret the test results. Based on an hydraulic fracturing stress measurement campaign at an underground liquefied petroleum gas storage project which locates in ZhuHai, China, this paper briefly describes the various uses of stress measurement, details of hydraulic fracturing test system, test procedure adopted and the concept of hydraulic fracturing in arriving at the in-situ stresses of the rock mass.


2021 ◽  
Author(s):  
Vil Syrtlanov ◽  
Yury Golovatskiy ◽  
Konstantin Chistikov ◽  
Dmitriy Bormashov

Abstract This work presents the approaches used for the optimal placement and determination of parameters of hydraulic fractures in horizontal and multilateral wells in a low-permeability reservoir using various methods, including 3D modeling. The results of the production rate of a multilateral dualwellbore well are analyzed after the actual hydraulic fracturing performed on the basis of calculations. The advantages and disadvantages of modeling methods are evaluated, recommendations are given to improve the reliability of calculations for models with hydraulic fracturing (HF)/ multistage hydraulic fracturing (MHF).


SPE Journal ◽  
2019 ◽  
Vol 24 (04) ◽  
pp. 1839-1855 ◽  
Author(s):  
Bing Hou ◽  
Zhi Chang ◽  
Weineng Fu ◽  
Yeerfulati Muhadasi ◽  
Mian Chen

Summary Deep shale gas reservoirs are characterized by high in-situ stresses, a high horizontal-stress difference (12 MPa), development of bedding seams and natural fractures, and stronger plasticity than shallow shale. All of these factors hinder the extension of hydraulic fractures and the formation of complex fracture networks. Conventional hydraulic-fracturing techniques (that use a single fluid, such as guar fluid or slickwater) do not account for the initiation and propagation of primary fractures and the formation of secondary fractures induced by the primary fractures. For this reason, we proposed an alternating-fluid-injection hydraulic-fracturing treatment. True triaxial hydraulic-fracturing tests were conducted on shale outcrop specimens excavated from the Shallow Silurian Longmaxi Formation to study the initiation and propagation of hydraulic fractures while the specimens were subjected to an alternating fluid injection with guar fluid and slickwater. The initiation and propagation of fractures in the specimens were monitored using an acoustic-emission (AE) system connected to a visual display. The results revealed that the guar fluid and slickwater each played a different role in hydraulic fracturing. At a high in-situ stress difference, the guar fluid tended to open the transverse fractures, whereas the slickwater tended to activate the bedding planes as a result of the temporary blocking effect of the guar fluid. On the basis of the development of fractures around the initiation point, the initiation patterns were classified into three categories: (1) transverse-fracture initiation, (2) bedding-seam initiation, and (3) natural-fracture initiation. Each of these fracture-initiation patterns had a different propagation mode. The alternating-fluid-injection treatment exploited the advantages of the two fracturing fluids to form a large complex fracture network in deep shale gas reservoirs; therefore, we concluded that this method is an efficient way to enhance the stimulated reservoir volume compared with conventional hydraulic-fracturing technologies.


Sign in / Sign up

Export Citation Format

Share Document