The Research And Application Of Imitation Of Oil-base Drilling Fluid System

Objective:Through our research, we find that during the process of exploration and drilling in Xinjiang oilfield there are so many problems about the difficult geological horizon that can’t be solved by the drilling fluid, the main problem is that the serious pollution caused by hydration swelling of dispersion and drilling fluid in the stratum cannot be clean up, and it would put us in a dangerous consequence in which some drilling accident would happen in the well. In order to keep and prove the production, in recent years, we are taking efforts to develop the old and difficult zones in the exploration process of Xinjiang oilfield. The Xinjiang oilfield is made up by many difficult zones, and the drilling fluid of many difficult well can only be the common one because of the cost to make the process long and slow. Every year, the problem about lacking of the function of drilling fluid may lead to a high cost of drilling in the difficult stratum(where pollution and accident happen easily). Obviously, the common drilling fluid couldn’t solve there problems well, however, the oil-base drilling fluid would cost more and lead to some other problems about pollution and positon(to store it) at the same time. So, we could use oil-base drilling fluid only in the drilling fluid engineering of important well.We can only change the system of drilling fluid to solve this problem, and we need to find this new system out immediately. Therefore, we started a research in order to make the achievement(a new kind of drilling fluid system) satisfy the safe drilling in the difficult stratum by its related character.Details:This topic are about the FK-1imitation of oil-base drilling fluid treating agent, and the main contents of this topic is about the FK-1imitation of oil-base drilling fluid treating agent and the two parts of FK-1imitation of oil-base drilling fluid system. We will assess the result of this project in time after the field test.FK-1imitation of oil-based drilling fluid treating agent after primary treatment for the research on the optimization method is grape sugar derivatives were modified, after the introduction of potassium ion in the glucose ring polymerization moderately, make its have strong hydrophilic group, improve the solubility in water. Itself for forming a semi permeable membrane principle has good shale inhibition, is through the introduction of potassium ions, using potassium ions embedded mechanism and glucose derivative synergy makes the stability of shale inhibition ability is stronger. We through consulting A large number of literature material, through A lot of screening, synthesis, and the evaluation of the indoor experiment, finally we common starch as the main raw material in the acid environment, by the initiator of A and B work together, in the isolated from oxygen environment, constant temperature reaction, generate FK-1treatment agent, then through neutralization, crystallization, filtration, drying treatment finally get A solid FK-1.FK-1genus chitosan polymer monomer derivatives, is a kind of weak polarity surface active substance, on its molecular structure with oil-wet methoxyl (OCH3) and hydrophilic hydroxyl (OH). Its cyclic molecules containing hydroxyl, its very strong water imbibition, can form strong hydrogen bond and water molecules. Hydrophilic hydroxyl adsorption in the surface of the wall rock or cuttings on the surface, the lipophilic group is out, and on the wall to form a layer similar to the water-in-oil drilling fluid adsorption of hydrophobic membrane, separates the moisture in the water in the strata shale and drilling fluid. The molecular structure of the hydrated K+can low, brought thin to clay hydration film, inhibit clay dispersion. So when FK-1filtrate in drilling fluid into the formation, the effect is different from ordinary fresh water, it can make the formation rocks occur to hydration. Proved through the experiment of drilling fluid shale FK-1to take off the water is not oil-based drilling fluid, but higher than that of KC1drilling mud and glycerin. Evaluate method:We mainly evaluate the FK-1copy oil-base drilling fluid treating agent aiming at its rejection capability and unctuosity. We evaluate its cutting roller recovery of shale, the contribution to the reduction rate of lubrication coefficient, and at the same time we can provide the proof to formula additive amount. With the dosage increasing of FK-1, the recovery of shale increase.It shows us that FK-1has a good capability to restrain shale. At the same time, the result of rejection capability obviously increase at the dosage7%. After7%with the dosage increase, the change becomes slowly. Through our analysis, the unctuosity of the drilling fluid becomes better if we put FK-1single-dosage in its base mud, and with the dosage increase,the increasing of unctuosity becomes faster. As FK-1single-dosage has a good capability to control shale and unctuosity, we can put it in in order to improve the function of drilling fluid. And we also find that the improvement of drilling fluid is in direct proportion to the additive amount of FK-1dosageFK-1imitation of oil-base drilling fluid system is mainly made up by its treating agent,assist treating agent, filtrate reducer, pH modifier etc. We may meet some problems during the research the agent of FK-1,so we must find out some methods or solutions to these problems in order to get the formula system which satisfies the field requirement. The research told us that, for the imitation of oil-base drilling fluid, the cutting roller recovery of mudstone and shale is high, the linear expansion rate of filtrate is low,that is to say, the drilling fluid has a good rejection capability. In the same circumstance, the friction coefficients and unctuosity of imitation of oil-base drilling fluid and oil-base drilling fluid are almost the same, and it’s better than TR drilling fluid, the research also shows us the same conclusion and a good capability of stratum protection.Through the compatibility experiment with mud, we compare the liquidity of drilling fluid which put in FK-1imitation of oil-base treating agent and assist agent. Generally speaking, according to different types of stratum and specific application requirement of the well,the additive amount of formula and the effect will be also different. Through the adjustment of formula additive amount, flow type agent and the base mud indoor, we can find out the best formula of drilling fluid and its convenient method for using. In the process of drilling, mud treatment downhole condition monitoring, control, comprehensive evaluation of FK-1copy oil-base drilling fluid system in dealing with complex formation, to perfect and further optimization of formula. Late on the analysis of log data can intuitive reflect FK-1imitation of oil-base mud real effect in the experiment provide the basis for evaluation.Conclusion:The FK-1imitation of oil-base drilling fluid treating agent is obviously better than TR drilling fluid and next to the oil-base drilling fluid on its rejection capability, unctuosity and stratum protection. At the same time, it resists salt and calcium pollution well and restrain mudstone-dispersed well to prevent collapse. The FK-1imitation of oil-base drilling fluid has a good capability to protect reservoir stratum.