Research Grant Details
Development of Bentonite Mineral as Drilling mud in the Petroleum Industry
Benefit to Oil and Gas
More investment window in Bentonite exploration in-country, reduced the rate of dependence on imported drilling mud by IOCs. The beneficiation and calcination of Bentonite is on-going. Test run of the drilling mud is being carried in the oil fields.
Ahmadu Bello University
In its final report submitted to the PTDF by the researchers, it was reported that the some of the clays studied were Bentonitic owing to the presence of smectite (montmorillonite) discover in them, but even after the clays were activated with sodium carbonate, their rheological properties did not meet the API standard until when about 10% of poly-ionic-cellulose was added to the clays. In the report, it was suggested that impurities such as SiO2, Fe and Ti might have caused the deficiency in the rheological properties of the clays. Therefore, a recommendation was made that required the upgrade/extension of the project such that these and other suggestions aimed at further improvement of the properties of the clays could be studied. This culminated into the submission of a proposal in the 2012 Grant Competition and after thorough assessment of the proposal, the project was recommended and approved as one of those that was approved for funding in the second research grant.
The second phase of this project covers further development of Nigeria's local clay by enhancing its qualities through impurity removal, further beneficiation by using formulation agents not adopted in the first phase such as the use of locally available viscosifier and blending of beneficiated clays with weighing agents to positively enhance rheological properties of the clays.
The main aim had been to thoroughly evaluate the clays in in terms of their being used for drilling operations. This was done with a view to use such information to provide a scientific estimate of the Bentonite potential of the country. In addition to samples from locations covered by the first phase of the project, additional location like Tongo in Gombe and Gambe in Adamawa States were also sampled. Formulations adopted were prepared using different proportions of Gum Arabic, Poly-ionic cellulose (PAC), after activating the Ca-based Bentonitic clays with different quantities (1 to 15%) of sodium carbonate. The procedure on the execution of the project adopted involved elemental analysis of raw samples using Neutron Activation Analysis (NAA) and X-Ray Fluorescence (XRF), characterization of samples based on elemental composition, analysis of levels of impurities, silica reduction using gravity method and particle size distribution analysis, activation of samples with sodium carbonate,
measurement of rheology of raw and treated samples, addition of weighing and viscosifying agents in different proportions and re-measurements of rheological properties until optimum values are recorded. Results obtained indicates that wet beneficiation as adopted in this study has proved to be more effective in ionic exchange between Ca and Na. The rheological and other physical properties of the clays attained the standard that is required for a drilling fluid used in oil and gas well drilling after addition of 12% sodium carbonate and 1.5g PAC. It was also discovered that when the formulation was allow to age (stay for 24hrs), it attained optimum rheological requirement with 12% sodium carbonate and just 0.8g PAC.
In summary, the project has successfully beneficiated clays from Pindiga and Fika Formations in
north-eastern Nigeria to the standard required for drilling operation. It is suggested that the beneficiated clays be simulated using VITUAL HYDRAULIC to assess its performance at field condition (down-hole condition).