Research On Well Test Interpretation Method Of MDT

MDT(Modular Dynamics Tester)is the third-generation cable formation tester from Schlumberger.When using the MDT test,the test time is short and is suitable for drilling and completion tests.In general,when the reservoir is thick,the fluid state of the formation presents a spherical flow.When the reservoir is thin,the flow state of the formation fluid appears as a radial flow,However,when the reservoir thickness is very thin and the physical properties are very good,the formation fluid may have a complex flow state of "spherical-radial flow",formation fluids may have a combined "spheroidal-radial" flow regime.The existing well test models for MDT test are spherical flow model and radial flow model,which are aimed at homogeneous reservoirs and complex reservoirs.However,there are no such reservoirs with natural fractures and good physical properties.The relevant well test model was established.In the thin layer with good physical properties,the composite flow regime test model "Spheric-radial flow" was not considered.Therefore,this paper establishes a thin reservoir with good properties.The MDT "spheroidal-radial flow" well test model considers the flow of fluid"spherical-radial flow" composite.At the same time,this paper establishes and solves the MDT spherical flow test model and MDT "spheroidal-radial flow" well test model under different geological conditions,and draws the corresponding typical well test pattern curve,which is applied to the flow stage.Divided and analyzed the influence of various model parameters on the model curve of MDT well test model.The main contents of this dissertation includes the following aspects:(1)For the homogeneous reservoir,the MDT spherical flow well test model for an infinitely large homogeneous reservoir is studied and an infinitely large homogeneous oil reservoir MDT"spherical-radial flow" is established.The "flow" well test model was used to draw the corresponding theoretical model curve,and the effects of parameters such as pipeline reservoir coefficient,skin factor,vertical and horizontal permeabilities on the pattern curve were analyzed in a targeted manner;(2)For dual medium reservoir,established the MDT spherical flow well test model and the MDT "spheral-radial flow" well test model for the dual-medium reservoir,and plotted the corresponding theoretical model curves,focusing on the consideration of the fracture capacity factor and matrix-to-crack influence of turbulence coefficient on the pattern curve;(3)For composite reservoirs,an MDT spherical flow test model in which the inner zone and the outer zone are homogeneous and a MDT "spheroidal-radial flow" well test model are established.The inner zone is a homogeneous MDT "spheroidal-radial flow" well test model in the double outer zone,and a corresponding sample curve is drawn,focusing on the analysis of the radius of the inner zone,the ratio of the energy storage of the inner zone to the outer zone,comparison of the flow ratio between the outer zone and the inner zone impact;(4)the useful reservoir parameters is obtained by application MDT well test curve to field,the measured results of well test model of radial flow,well test model of spherical flow and well test model of "spheroidal-radial flow" are compared and analyzed.