Determination of the clay-polymer interaction for drilling mud applications

This thesis is about determining the clay-polymer interactions for drilling mud applications. Drilling fluids in 1901's first used in the rotational drilling method as the beginning of the drill technology. The first drilling fluid used was water. Drilling with suspension of the clay, different than water present positive influence and thus emerged a new drillling mud. Drilling mud in the modern sense was obtained in 1921 with the addition of various additives to control the properties of the mud. Many developments have occurred in the drilling fluid in the petroleum industry and are subsequently applied to the wells industry. Today, drilling fluid systems constitute a significant cost for the holes dug wells with rotary method. Thus, the success of drilling operations, the drilling fluid of drillers determined by its ability to control the physical properties. The drilling mud must have; ability to transport cutting chips to surface, lubricate than cool the drilling tools and drilling bits, prevent collapsing of the drilling well, control the drill bearing pressure and pump affortlessly. Researches showed that all pre testings about detecting clay minerolgy, chemically identification, claasification of the different brand clays, enlightining the inner structure, swelling ratio in the water. Other researches about clays becoming jelly like substance are the results of the adding salt to clay dispersion and pH effects on the suspensions. The developments in the usage of the clay particules and similar structured mixtures are the reason researches are focused on the effects on the supplement matters and polymers. Characterised with the different interactions with clays and supplimental materials, shows us the change in the distance between the layers of surface loads and silica layers can be differ by interation between them. In applied experiments, the aim is the enhancing the viscocity and the flow rate properties of the drilling mud. The studies about drilling fluids are about rating the combination and concentration of the following clay minerals; first Ca-Bentonite which has high adsorbation and swelling porperties that provided from Balıkesir Dereiçi, second is Sepiolite which has high viscocity, fiberic structure matrix and cream like thickness, as a third one is Lime (slacked lime). By preparing the minerals; bentonite, sepiolite and Lime (slacked lime) with concentration %1 up to %4 concentration dispertions, to check the rheologic properties of them. Observations show that Bentonite and Lime (slacked lime) suspensions are suitable for newtonian flow models however sepiolite is suitable for plastic fluid model. The characteristic properties of these clays are tended also. The current studies to enhance the properties of polymers increased with developing industrial applications of polymers. The researches are focused on finding additions to the most effective polimers and particle improvements of the properties of polymer. The naturally layered structure of clay is acknowledged to be an effective addition to polymer because it can be mix easily in polymer compound. Therefore, the studies to determine the preparation methods, the characterization, and rheologic properties of the clay polymer have been started. Adding different concentration of HEC and starch to the mixture used in experimental studies to increase viscocity, flow properties and prevent the fluid loss. In Bentonite and HEC dispertions, the improvement is observed in viscocity values by adding HEC. Increasing HEC concentration amount in the polymer, the surface matrix of it filled with HEC and by this the resistance against flow is increased. Using Electrokinetic properties of the clay as a benefit; the HEC concentration that added to the negative charged clay granules seems to be covered by HEC polymers and this increase the rheologic properties of the clay. Considering the X-Ray diffractions analysis the difference between concentration layers "d" is stayed same by this method. 0,5 to 0,6 (g/l) concentration of the sepiolite and HEC suspensions, creates a increase in viscocity values. High concentration of Sepiolite and HEC, the viscosity decreases. Polymers which have electrokinetic properties, are observed in niddle forms Sepiolite packs there are countless zeta potantial results, indicates that Sepiolite is holding in the edges not pass between layers. Considering the rheological, zeta potantial and X-Ray readings, there is only one outcome as polymers do not interract when used as Lime (slacked lime), HEC and Lime (slacked lime), Starch dispertions. Starch mixture of α-amylose and amylopectin, which is a form of storage of glucose in the plant. Starch, amylose is a straight chain consisting of repeating units of the α -D- glucose α -1, 4 glycosidic bond is a branched polymer. Starch and Polymer compounds are mixed to observe if there is an interaction between them. However starch polymers cause no dissolving or getting lumpy. It did not pass between the layers or even attach to the layer surface, it did not interact. The way they interact with the polymers of the clay in the previous section were examined by rheological and zeta potential measurements and in study. Looking at the drawn graphics was selected the most suitable concentration for bentonite and sepiolite. 1(g/l) polymer concentration was elected we will prepare for drilling muds. Clay-water ratio according to the API standards are such that 22.5 g clay 350ml, but the required 500 ml of drilling mud for API 500 ml 7 types of rheological measurements, including drilling mud clay 32.15 grams while maintaining the ratio of the standard was prepared. These seven drilling mud; Bentonite, HEC+Bentonite, Starch+Bentonite, HEC+Bentonite+Sepiolite, Starch+Bentonite+Sepiolite, HEC+Bentonite+Lime, Starch+Bentonite+Lime. Best results in test done in prepared drill clays, show that the best selections for rheological properties are Sepiolite, Bentonite and polymers (that used in experiments). After mixing the Sepiolite in the mixer, the fibers are released and it starts to hold water and becomeing jelly like substance, as a result of its mechanical properties. In filtering tests the Lime (Slacked lime) mixtures, can not hold water in their structure and release it in very short time periods. Thus it is an expecting result because of the usage of the Lime in Drill wells as a precipitation of fluids.