Study On Horizontal Well Productivity Of Sanzhan Gas Held

Compared with conventional vertical wells, the contact area with oil or gas reservoir ofhorizontal wells has been increased greatly that it can effectively improve the productivity ofwells and then guarantee the economic benefits of the reservoir development. Even though ithas been years for using the horizontal well to develop oil reservoir, gas reservoir is in theminority. The gas bearing area of Sanzhan gas field is large and geological reserves are high.However，the gas field with low pressure and low production rate. The main driving type isweak edge water drive. The single well productivity is low. Thus, it is of great significance tostudy on developing this kind of reservoirs with horizontal wells.In order to meet the needs of productivity calculation of horizontal wells in gas reservoir,In combination with the actual characteristics of the reservoir construction, gas layers andgas-water distribution, this paper selects the favorable block for gas field development tofound the physical model of horizontal wells in the middle-shallow gas layers in Sanzhan gasfield. Considering the effects of heterogeneity and skin factor, the productivity analysisformula of horizontal well is improved. Finally, the production calculation formula which issuitable for horizontal well of gas reservoir is given. Do productivity prediction andcorrelation according to the actual datas of well San2-Ping1drilled in Sanzhan gas field. Theresults show that the error is very small which proved the theory model is reasonable. Andthen optmize the most suitable production calculation formula of horizontal wells for Sanzhangas field in Daqing. The analysis of influencing factors on the productivity of horizontal wellswith open hole completion or perforation completion show that deviation caused by eachfactor is different. At last, development potential of Sanzhan gas field is analyzed. On the baseof the productivity prediction, do economic evaluation with different gas price of gas wells ineach block respectively and get the economic limits of different blocks with different gasprices as well as making judgments whether horizontal wells are suitable for each block inSanzhan gas field.Less researches of productivity prediction methods of horizontal wells is made at homeand abroad, so the study of this paper will lay the foundation for the evaluation ofmiddle-shallow gas reservoir and later development adjustment, which also has a guidingsignificance in the development of middle-shallow gas reservoir.