Crisman Annual Report 2009 - Harold Vance Department of ...

More documents

Recommendations

Info

Improved Permeability Predictions using Multivariate Analysis Methods Introduction Predicting rock permeability from well logs in uncored wells is an important task in reservoir characterization. Due to the high costs of coring and laboratory analysis, typically cores are acquired in only a few wells. Since most wells are logged, the common practice is to estimate permeability from logs using correlation equations developed from limited core data. Most commonly, permeability is estimated from various well logs using statistical regression. For sandstone reservoirs, the logarithm of permeability can be correlated with porosity, but in carbonate reservoirs the porositypermeability relationship tends to be much more complex and erratic. Objectives In order to improve the permeability estimation in complex carbonate reservoirs, several statistical regression techniques have been tested in previous work to correlate permeability with different well logs (Lee, Arun and Datta-Gupta, 2002; Mathisen, Lee, and Datta-Gupta, 2003). It has been shown that statistical regression for data correlation is quite promising, but using all the possible well logs to predict permeability may not be appropriate because the possibility of spurious correlation increases as more well logs are used. Therefore, the objective of this study is to further improve permeability prediction by selecting appropriate well logs for data correlation via variable selection procedures. Approach In statistics, variable selection is used to remove unnecessary independent variables and give a more robust prediction. We will apply variable selection methods to the permeability prediction procedure to improve permeability estimation. Specifically, we have proposed a new method combining the stepwise regression with Alternating Conditional Expectation (ACE) techniques and will compare the proposed method with two other methods: the tree regression and the Multivariate Adaptive Regression Splines (MARS) method. Accomplishments Three methods are tested and compared using data from a complex carbonate reservoir in west Texas: Predicted vs. Measured MSE=1.9728 MAE=1.0682 =0.68227 10 -2 10 -1 10 0 10 1 10 2 10 3 Measured permeability the Salt Creek Field Unit (SCFU). The results of SCFU show that the stepwise regression with the ACE method outperforms the other two methods in permeability prediction. The figure shows the result of the stepwise regression with the ACE method vs. true permeability for a blind test data set. Project Information 3.2.13 Improved Permeability Predictions using Multivariate Analysis Methods Related Publications Lee, S. H. and Datta-Gupta, A. 2002. Electrofacies Characterization and Permeability Predictions in Carbonate Reservoirs: Role of Multivariate Analysis and Non-parametric Regression. SPE Reservoir Evaluation and Engineering 5 (3): 237-248. DOI 10.2118/78662-PA. Mathisen, T., Lee S. H., and Datta-Gupta, A. 2003. Improved Permeability Estimates in Carbonate Reservoirs Using Electrofacies Characterization: A Case Study of the North Robertson Unit, West Texas SPE Reservoir Evaluation and Engineering 6 (3): 176-184. Contacts Akhil Datta-Gupta 979.847.9030 a.datta-gupta@pe.tamu.edu Jiang Xie Depth 6220 6240 6260 6280 6300 6320 6340 6360 6380 6400 6420 Measured permeability Permeability vs. Depth CRISMAN INSTITUTE Predicted permeability Permeability Predictions from Well logs Using Stepwise Regression with ACE (Alternating Conditional Expectations) for the Salt Creek Field Unit, West Texas. Crisman Annual Report 2009 77
CO 2 Mobility Control using Cross-Linked Gel and CO 2 Viscosifiers Objectives 1. Investigate and test different approaches in the laboratory to control CO 2 mobility during CO 2 flooding to increase the overall efficiency. 2. Develop a simulation model which would incorporate the CO 2 viscosity relationship with pressure, then use this model to predict viscosified CO 2 flooding efficiency in comparison with pure CO 2 flooding. Accomplishments The visualization of CO 2 flow within core using CT- Scanning provides us with a more direct observation for the CO 2 flood fronts in the core. We have studied two approaches to control CO 2 mobility: HPAM/ Cr(III) gel conformance control treatment, and the direct increase of CO 2 viscosity using viscosifier chemicals (PVAc or Polysiloxanes). For the study of gel conformance control, crosslinked HPAM/Cr(III) gel was applied to fractured cores in order to get incremental oil recovery. We have tested 10,000 ppm of high concentration gel and found out it had a better stability when compared with the 3,000 ppm gel we used previously. The 10,000 ppm gel appeared to be more stable and also gave a higher pressure drop in CO 2 flooding, which means better mobility control. For the study of CO 2 viscosifiers, a controlled CO 2 flooding experiment using pure CO 2 was conducted and the expected low recovery was obtained due to rapid breakthrough of CO 2 through the fracture. The first low molecular weight viscosifier was studied and we observed significant differences in CO 2 flood front images. A more uniform, piston-like CO 2 flood front was formed in the viscosifier case, suggesting a reduction in CO 2 viscosity. Higher oil recovery was also observed using viscosified CO 2 . A black-oil pseudo-miscible model for an oil field in Peru was developed using data from one of the wells. To account for the increase in CO 2 viscosity, new viscosity/pressure relationships were integrated into the simulation model. We are currently simulating viscosified cases to develop cost benefit relations. Future Work More viscosifier chemical structures will be studied to compare the efficiency differences between low 78 and high molecular weight viscosifiers. The injection scheme will be altered to reflect field sequence of events: we will begin with pure CO 2 until no more oil is recovered, and then we will begin injecting viscosified CO 2 to determine the incremental recovery caused by viscosified CO 2 after pure CO 2 injection. We will also develop simulation tools capable of accounting for viscosified CO 2 cases. End of Coreflood for 3000 ppm gel: End of Coreflood for 10,000 ppm gel: Gel Strength Study - (red/yellow color shows gel distribution after CO 2 flooding, blue color is the sandstone matrix. The sandstone core is fractured both horizontally and vertically. CO 2 injection from right to left.) Pure CO 2 flood image (after 1.6 PV CO 2 injected) Viscosified CO 2 flood image (after 1.3 PV CO 2 injected) Comparison of pure CO 2 flood front and viscosified CO 2 flood front. The pure CO 2 flood case has most of the CO2 concentrated in the fracture region. A more stable piston-like displacement is observed in the viscosified CO 2 case. Project Information 3.4.4 Application of X-Ray CT for Investigating Fluid Flow and Conformance Control during CO 2 Injection in Highly Heterogenous Systems Contacts David Schechter 979.845.2275 david.schechter@pe.tamu.edu Shuzong Cai CRISMAN INSTITUTE Crisman Annual Report 2009
Page 1 and 2:
Harold Vance Department of Petroleu
Page 3 and 4:
Issue 3, February 2010 Stephen A. H
Page 5 and 6:
Combustion Assisted Gravity Drainag
Page 7 and 8:
6 Crisman Annual Report 2009
Page 9 and 10:
Summary The Crisman Institute has t
Page 11 and 12:
Membership History The Crisman Inst
Page 13 and 14:
12 Crisman Annual Report 2009
Page 15 and 16:
An Advisory System for Selecting Dr
Page 17 and 18:
A procedure to measure the viscosit
Page 19 and 20:
PRISE - Petroleum Resource Investig
Page 21 and 22:
Gas Shales Simulation and Productio
Page 23 and 24:
Characterization of Rock Transport
Page 25 and 26:
An Analytical Approach to Model Sha
Page 27 and 28: P90 P50 P10 Fig. 3. P10, P50 and P9
Page 29 and 30: Density distribution from heat tran
Page 31 and 32: Experimental and Simulation Modelin
Page 33 and 34: Fig. 1. Set up of displacement appa
Page 35 and 36: Study of Solvent-Based Emulsion Inj
Page 37 and 38: Investigation of Hybrid Steam-Solve
Page 39 and 40: Experimental Studies of Steam Injec
Page 41 and 42: Combustion Assisted Gravity Drainag
Page 43 and 44: Well Spacing and Infill Drilling in
Page 45 and 46: Experimental and Numerical Simulati
Page 47 and 48: Enhanced Oil Recovery of Viscous Oi
Page 49 and 50: Alternate Power and Energy Storage/
Page 51 and 52: Propagation of Induced Hydraulic Fr
Page 53 and 54: » Use forward modeling of wellbore
Page 55 and 56: Decision Matrix for Liquid Loading
Page 57 and 58: fractions involved, a detailed sens
Page 59 and 60: Transient Multiphase Sand Transport
Page 61 and 62: Carbonate Heterogeneity and Acid Fr
Page 63 and 64: Fracture Aperture Variation Caused
Page 65 and 66: that contained 12 wt% HCl showed th
Page 67 and 68: Evaluation of Polymer-Based In-Situ
Page 69 and 70: Modeling of Discrete Fracture Netwo
Page 71 and 72: Thermo-Poroelastic Finite Element A
Page 73 and 74: Measurement and Correlation of Gas
Page 75 and 76: The falling body viscometer is sele
Page 77: Fracture permeability (md) 12 10 8
Page 81 and 82: (a) Standard EnKF for permeability
Page 83 and 84: Aquifer Management for CO 2 Sequest
Page 85 and 86: Bibliography List of Theses and Dis
Page 87 and 88: » Florence, Francois; Validation/E
Page 89 and 90: » Diyashev, Ildar; Problems of Flu
Page 91 and 92: » Freeman, C.M., Ilk, D., Moridis,
Page 93 and 94: and Catalyst. Paper presented at th
Page 95: Exhibition, San Antonio, Texas, 24-
show all

Crisman Annual Report 2009 - Harold Vance Department of ...

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?