Feasibility Study Of Borehole Radar To Detect Oil And Gas Reservoir

At present,borehole radar has been widely used in engineering,surveying and other fields,and has played an important role,but its application in the petroleum field has lagged behind.Traditional logging techniques such as sonic logging have a small detection range and can only detect small-scale structural anomalies in the wellbore;conventional terrestrial geophysical methods such as seismic exploration have a large detection range,and can detect structural anomalies of a size above 100 meters;drilling radar detection is drilling The hole is carried out,the detection range is between the two,just fill the gap of the detection distance,and because of its higher resolution,the obtained information is more reliable.Therefore,it is important to demonstrate the feasibility of borehole radar in logging applications.This feasibility includes the identification of geological bodies and the identification of different types of reservoirs.If so,its application will be tested.The well industry brings new possibilities.Based on the above facts,this paper uses the open source software gprMax 3.0 to simulate a series of drilling radar applications in petroleum logging.First,consider the structural information that is inevitably detected during the radar logging process.The identification of such information can effectively judge the current drilling geological environment and have positive significance for judging the position and reserves of the reservoir.In this paper,four common layered structural models are designed,including horizontal layer,inclined layer,thin layer and fault.The signal characteristics of the radar profile obtained by forward modeling are as follows: the reflection of the drilling radar on the horizontal layer is “K” type,up and down The reflected wave energy of the layer is the same;the reflected wave energy of the inclined layer is different,and the refracted wave with stronger energy appears;the thin layer can be identified by the extension of the refracted wave in the wellbore;the fault layer has obvious fault plane Reflected waves,but the anomalous bodies inside the fault are not recognized.At present,there are many types of oil reservoirs known in the world.In recent years,deep carbonate karst weathering crust-hole reservoirs have gradually become one of the most important reservoir types in exploration and development.The ability to identify different reservoirs in carbonate rock.Through the collection of data,four common carbonate reservoirs were designed,including pore-type reservoirs,fracture-type reservoirs,fracture-cavity reservoirs and fault-type reservoirs.The simulation results show that the borehole radar is beaded.The hole-type reservoir has a good recognition effect.It can identify the bead shape of the parallel axis of the shaft and identify the number of holes.However,the number of holes cannot be discerned for the hole group whose axis is perpendicular to the well axis;the direction is parallel to the well axis.The crack zone can be effectively identified,including the identification of crack length,extension direction and fracture zone orientation;the fracture-cavity reservoir can also be identified;for fault-type reservoirs,the fracture direction is basically perpendicular to the well axis due to geological action,and the results indicate that the borehole Radar identification of such reservoirs is not feasible.There are many influencing factors for the detection of underground media by borehole radar.There are also many problems in the change of borehole environment and the setting of borehole radar system.Therefore,this paper designs related models to explore the factors affecting the detection effect of borehole radar,such as the expansion of the wellbore,the diameter of the wellbore and the salinity of the water-based mud,and the setting of the basic parameters of the antenna.analysis.The results show that the borehole radar has obvious signal response to the expansion phenomenon;the mud mineralization affects the mud conductivity,the conductivity increases,the return loss increases,and the excessive conductivity leads to the echo phase distortion;the caliper,mud The relative dielectric constant and the change of the transmission and reception distance have little effect on the abnormal body echo signal of the borehole radar;the antenna center frequency affects the drilling radar resolution,and also increases the electromagnetic wave loss.The production should be set as needed.