Correction and supplementingation of the well log curves for Cuu Long oil basin by using the Artificial Neural Networks

Abstract

When drill well for the oil and gas exploration in Cuu Long basin usually measure and record  seven curves (GR, DT, NPHI, RHOB, LLS, LLD, MSFL). To calculate the lithology physical parameters and  evaluate  the oil and gas reserves,   the softwares  (IP, BASROC...) require that all the  seven  curves must be recorded completely and accurately from the roof to the bottom of the wells.  But many segments  of the curves have  been broken,  and mostly only 4, 5 or 6 curves have could recorded. The cause of the curves being  broken or not recorded  is due to the heterogeneity of the environment and the lithological  characteristics of the region. Until now  the improvements of  the measuring recording equipments  (hardware) can not  completely overcome this difficulty.

This study presents a method  for  correction and supplementing of the well log curves by  using the Artificial Neural Networks.        

Check by 2 ways: 1). Using the good recorded curves, we assume some segments  are  broken,  then  we corrected and supplemented these segments.  Comparing the corrected and supplemented value  with  the good recorded  value. These values coincide. 2). Japan Vietnam Petroleum Exploration  Group company LTD  (JVPC) measured and recorded nine driling wells. Data of  these nine  wells  broken. This study  corrected and supplemented  the broken segments, then use the corrected and supplemented  curves to calculate  porosity. The porosity calculated in  this study for  9  wells has been used by  JVPC to build the mining production technology diagrams, whle the existing softwares can not calculate this parameter. The testing result proves that the Artificial Neural Network model (ANN) of this study is great tool for correction and supplementing  of  the well log curves.