Descriptive statistical analysis for the PPG field applications in China: Screening guidelines, design considerations, and performances

Abstract

Preformed particle gels (PPGs) have been widely applied in waterflooded mature oilfields to improve reservoir sweep efficiency and control water production. Successful PPG applications in oilfields require comprehensive guidelines on where and how PPG treatments can be best applied. To establish such guidelines, a data set is first constructed by collecting 678 successful PPG treatment data from SPE technical papers, papers published in Chinese, and field applications reports from 2001 to 2015. Critical information regarding reservoir characteristics, injection well conditions, injection parameters, and treatment performances, is included in the data set. Descriptive statistical analysis methods including histograms, and scatterplots are used to interpret of the main features of the amount of data. Histograms display the distribution of each parameter and can provide guidance on where PPGs can be best applied; scatterplots uncover relationships between two variables and can aid in interpreting how to design injection parameters and find out the critical factors affecting the treatment performances. After comprehensive data analysis, the first application guidelines for PPG treatments are established. Results show that PPGs can generate large volumes of incremental oil production and significantly reduce excess water production. Successful PPG treatments require a large volume of PPG injection with a low suspension concentration. The injection volume highly depends on the daily water production rate. Incremental oil production increases with the increase of injected PPGs. PPG treatment efficiency is defined herein as incremental oil production per ton PPGs injected. Although reservoir type can affect the treatment efficiency, the better efficiency always comes from the injection wells which have production wells with a higher liquid production rate. Treatment timing should be considered as a critical factor affecting the effect of water reduction. This paper provides instructional guidelines for project design from which the success rate of PPG treatments in injection wells can be improved.