Evdokimova E.,Heriot Watt Institute of Petroleum Engineering
Proceedings - SPE Annual Technical Conference and Exhibition | Year: 2013
According to the generalized Western Siberia statistics only 25-30% of low resistivity reservoirs are successfully identified and evaluated using log dataset. The main purpose of the investigation is development the appropriate wireline log interpretation methodology which helps to identify the low-resistivity J1 1 formation of Z oil field. First of all the common causes of the low resisitivity pay occurence were investigated using published literature sources. Then the wells where the productive J 1 1 formation was characterized by anomaly low resistivity (Rt<5 Ohm*m) was determined. Then the concentration of conductive minerals was applied using Ezhova A.S.chart. For the purpose of exact estimation of Rt the conductivity that was not registrated by induction tool was calculated for each wells. This value was used for correct formation resistivity determination. As a result of the work performed the suggested methodology was succcessfuly implemented and recommened for using for Saturation evaluation throughout the low-resistivity pay in the Z oil field.
Hu X.,Sinopec |
Hu X.,Heriot Watt Institute of Petroleum Engineering |
Zheng S.,Heriot Watt Institute of Petroleum Engineering |
Zheng S.,China University of Petroleum - Beijing |
Xinan Shiyou Daxue Xuebao/Journal of Southwest Petroleum University | Year: 2012
The pressure deconvolution result is very sensitive to the initial reservoir pressure, and the error in this parameter must be controlled within 0.5%. It requires at least two different flow periods to determine this parameter by Levitan's method, and it is very susceptible to such factors as nonlinearity in pressure and rate data. A new deconvolution algorithm based on pressure derivative is presented, and it's in sensitive to the initial reservoir pressure. Moreover, only one flow period can be used to determine its value. Through detailed analysis in this paper, this algorithm can tolerate both errors in pressure and rate.
Falahat R.,Heriot Watt Institute of Petroleum Engineering |
Shams A.,Heriot Watt Institute of Petroleum Engineering |
MacBeth C.,Heriot Watt Institute of Petroleum Engineering
73rd European Association of Geoscientists and Engineers Conference and Exhibition 2011: Unconventional Resources and the Role of Technology. Incorporating SPE EUROPEC 2011 | Year: 2011
In this study, importance is drawn to the role of engineering principles when interpreting and estimating dynamic information from 4D seismic data. It is found that in clastic reservoirs the principal parameters controlling mapped 4D signatures are not pressure and saturation changes per se, but the changes scaled by the corresponding thickness (or pore volume) of the reservoir volume that these effects occupy. Indeed, pressure and saturation changes cannot be recovered by themselves, and this is true for all data interpretation and inversion procedures. This understanding is validated both with numerical modelling and analytic calculation. Fluid flow studies also indicate that the impact of gas saturation on the seismic can be written using a linear term, and that inversion to gas saturation can only yield the thickness of the distribution. The above has provided a basis for a linear equation that can be used to easily invert for pressure and saturation changes. Quantitative updates of the simulation model can be achieved by comparing scaled dynamic changes from the simulator with the inverted observations.