Research And Application Of SH Vegetable Gum Drilling Fluid

In recent years, with the rapid development of drilling projects, the demand of people for vegetable gum drilling fluids is growing. And then there are some practical problems for those vegetable gum drilling fluids(SM, for example) which were proved being has good qualities, such as lack of raw materials, too expensive and so on. Consequently that developing a new vegetable gum drilling fluid which has good qualities with wide raw materials and proper price is necessary and worthful.For the purpose of research, the approach of integrating theory with practice is adopted in this thesis. On the one hand, this paper makes an analysis of vegetable gum drilling fluids from theoretical, the details as fellow: the chemical composition of vegetable gum drilling fluids and its physical and chemical property, the rheological properties, stability, versatility and its mechanism, special function and its mechanism of vegetable gum drilling fluid. On the other hand, based on a great deal of field investigation, SH vegetable gum has been selected to principal component of the new drilling fluids. The best formulation of SH vegetable gum drilling fluid is picked up by laboratory tests and the capability test has been done to this fluid. There are mainly the following details:1. The conclusion that vegetable gum drilling fluids is one of viscoelastic fluids and its rheology equation can be described by power law model has been summed up. There is a close connection between the capability of vegetable gum drilling fluids and its rheological properties.2. Three special function of vegetable gum drilling fluid——protect coring function, viscoelastic vibration damping, frictional resistance functions are introduced and the mechanism of each special function is analyzed. The advantages of each special function are concluded.3. The best formulation of SH vegetable gum drilling fluid which is picked up by laboratory tests is: 2%SH+8% NaOH. That the capability of this drilling fluid is comparable with SM's is proved by laboratory tests.4. A method for collocating SH vegetable gum drilling fluid has been concluded——SH powder is put in firstly, NaOH as a slurry treating agent has been put in after 30 minute's mechanical agitation. And a series of controls for using SH vegetable gum drilling fluid in practice are established.With the field drilling applications, SM vegetable gum drilling fluid is proved to be satisfactorily meeting the demands of geological boring and there are a lot of advantages of this drilling fluid such as good core sample, high coring rates, excellent capabilities of lost circulation and suspension and removal of debris, excellentanti-shear shinning and so on.