Sandstone Reservoir Horizontal Well Completion Method Is Preferred

The well completion is a relatively independent technical engineering that joins the well drilling with the oil recovery. The optimization of well completion methods is the most important link of them.For the horizontal wells in unconsolidated sand,different completion methods have different sand control results which lead to different formation damage,and then result in dissimilar deliverabilities,and finally cause different economic benefits.Therefore,whether the completion methods for horizontal wells are reasonable or not directly affects whether the next development is well runned or not,and directly affects the future operation benefit. In addition, the unconsolidated sand is present widely all over the world and the horizonal well is increasing day by day and the horizontal well completion is more and more important. All of the above are just the reasons because which we research into the optimization of horizontal well completion methods.In this paper we take well completion method as optimizing object,from the point of view of well completion engineer,carry on a series of studies on the optimization of the horizontal well completion methods for unconsolidated sand,which include:Firstly , the sanding mechanism and sanding prediction and sandcontrol methods for unconsolidated sand are researched deeply.Secondly.the following are introduced detailedly containing the ros and cons and the conditions of application of four sand control completion methods(slotted liner,wire wrapped screen,open hole gravel packing,casing gravel packing) and two non-sandcontrol completion methods (open hole, perforating) of horizontal well.Through dividing near wellbore flow regimes,the skin factor caculation of the six methods is deeply and carefully studied and based on the commonly-used deliverability calculation formula for ideal open hole horizontal well,the specific deliverability calculation formulae under actual well completion condition are deduced, which offer the reliable formulae for subsequent deliverability forecast.Thirdly,considering synthetically the factors which affect the optimization of well completion methods for unconsolidated sand.The factors include geology, hole stability,sanding,engineering measures and so on.The completion methods that are suitable for horizontal well are analysed,and the flow chart for completion optimizing is drawn.Fourly,several common methodologies of economic evaluation are introduced detailedly,which offer the theoretical basis for economic evaluation of well completion and final optimization. Fifly,according to the above thinking,the program for optimization of horizontal well completion in unconsolidated sand is written by the VB language,which is successfully used in one horizontal well named D5h of BZ25-1 oil field.The optimized completion method is consistent with the practice,and the forecast deliverability is similar to the result of well test,which shows that the research method in this paper has a certain feasibility.