Bottomhole treating pressure, calculation

The physical properties of foams are changed by both the fluctuations in the surface rates of components and the temperature and pressure gradients the foam experiences as it travels down the wellbore and into the formation. Bottomhole treating pressures (BHTP) can be calculated as follows ... 

The use of the bottomhole treating pressures enables the fracture parameters to be calculated more accurately. As well, the continuous or dispersed phases can be altered as the treatment progresses in order to achieve maximum fracture propagation. The more accurate the prediction of the bottomhole pressures, the more reliable the data can be to create the best possible stimulation treatment. 

Hydraulic properties, that is, friction-loss calculations of proppant-laden fluids or slurries, are very important not only in the design of any hydraulic fracturing treatment but also in real-time monitoring of fracturing treatments. Recent advances (27, 28) in real-time fracture analysis have necessitated an accurate knowledge of bottomhole treating pressure (BHTP). To estimate BHTP, an accurate prediction of friction pressures of fluids in the flow conduit is required. It is possible to obtain the BHTP from the surface pressure with the following equation ... 

Manual calculations of these relationships would not be timely enough to keep pace with the varying surface treating pressures. Microprocessors enable the calculations to be completed as soon as the input parameters change. Therefore, more rapid changes in volumetric rates at surface can occur, and the bottomhole quality is kept constant. Bottomhole foam quality calculations do not generally encompass heat transfer from formations to the fluids. 

Implementation of an on-site computer control unit eliminates the need for mechanical systems, and enables real-time computation of bottomhole pressures. Monitoring techniques and pressure calculation methods vary extensively throughout the service industry. However, the measurable parameters such as surface treating pressure, liquid and gas injection rates, proppant concentration, and slurry temperature are the parameters that must be used to determine the bottomhole pressures. 

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See also in sourсe #XX -- [ ]

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