Drilling Magazine Media Intelligence, Contextual Wisdom
Regarding cement design, what domestic companies and research centers desire is maybe a development of standards for quality control methods for drilling cement additives under applicable conditions, which in turn can satisfy country’s oil and gas field needs and have desired quality indexes. Research institute of oil industry as an independent research institute and the right arm of Iran’s oil company research has accomplished effective tasks considering development plans of oil ministry for localization and design of different drilling cement additives. Some of these proceedings are applicable in industry and some of them are at field test level. Research institute of oil industry has done two phenomenal objectives; one is super lightweight cements and the other is elastic cement. These technologies have been used in 21 wells and had acceptable results. Also national plan of KIMIA in order of localization of all drilling cement additives and at the first pace by studying of 10 number of cement additives, is at its last phase of field test and we hope to see prosperous results of this project. Quality control of cement additives One of the challenges of oil industry is the instructions and standards of quality assessment of drilling cement additives that is needed to be investigated deeply. For the sake of assessment and quality control of a new additive that is bought from any company, there should be a specific standard that is suitable for Iran’s fields. Vast companies like Schlumberger and Halliburton are one of the famous ones producing drilling cement additives and also provide cementing services. Additives used in these companies have well-defined standards that accordingly quality control is carried out. In Iran it is not possible to
” An additive is said to be qualified that can be applied to that formations alike Iran’s. However, it can be worked properly under normal conditions and temperature but in the case of some Iran’s oil field conditions that both temperature and pressure is high and also existence of gas, the same additive will not have desirable results”.
use all of the produced cement additives of the same company at once, So, for purchasing any of the required cement additives and usage of it in the cement slurry formulation there has to be a reference to approve these additives. If it is intended to approve these additives on the basis of international firm’s standards, each one of the additives is a project that has to be investigated individually and because of high cost it is not economical to do so. So Research institute of oil industry according to Iran’s fields and with the cooperation of national Iranian south oilfield company produced a standard method and assesses every purchased cement additive from any company according to that. However, unfortunately other contractors and operators in drilling industry do not accept this method and quality standards so it should be planned for this in the future and apply all of the expert’s ideas in one method. In quality control of drilling cement additives, regarding type of additive, it may not be required to investigate a specific parameter for a sole additive but generally, for a whole additive all parameters have to be investigated. Paramount factors in cement slurry are: compatibility of additive with cement, effectiveness on slurry, effects on specific weight, thickening time, free water, compressive strength, gel strength, dynamic and static filter loss and gas invasion test. Considering additives type like filter loss controller that is used in drilling industry, in assessment of this additive filter loss and gas invasion in cement slurry have to be investigated. Important debate regarding retarders is cement thickening time, prime application of half thickening additive for cement slurry is to avoid thickening of slurry according to consumption quantity and temperature. Another important additive in use in drilling industry is gas migration controller .In investigation of such an additive some important parameters(filter loss, half thickening time, gel strength and rate of gas migration though cement slurry) have to be considered and the only institute that can do these tasks is Research institute of oil industry because this institute is equipped with gas invasion apparatus along with gel strength apparatus that only Schlumberger company has this one in Malaysia.
Quality control is different according to operational conditions and oil filed specifications. An additive is said to be qualified that can be applied to that formations alike Iran’s. However, it can be worked properly under normal conditions and temperature but in the case of some Iran’s oil field conditions that both temperature and pressure is high and also existence of gas, the same additive will not have desirable results.
Another important debate is the compatibility of an additive with other additives. One additive can be acceptable regarding quality but does not have proper results along with other additives. Especially in Iran which all additives do not belong to the same package of a company this is of paramount importance. As 50 percent of additives are available in Iran so another additives that have to be purchased, should undergo compatibility investigation with other available additives in Iran and have to meet all of the Iran’s specific standards from all of the fields. Examples of delicate fields in Iran regarding cementing job are Maroon, Ahvaz, Bibi-hakimeh, Azadegan, Sarvak, and Cheshmeh-khoon and exploration wells.
Author: Dr.Hamidreza Soltanian