|
| << vorige | volgende >> |
Tijdschrift beschrijving
Alle jaargangen van het bijbehorende tijdschrift
Alle afleveringen van het bijbehorende jaargang
Alle artikelen van de bijbehorende aflevering
Details van artikel 11 van 16 gevonden artikelen
| Titel: |
New Additives for Minimizing Cement Body Permeability |
| Auteur: |
Talabani, Soran Hareland, Geir Islam, M. R. |
| Verschenen in: |
Energy sources. Part A, Recovery utilization and environmental effects |
| Paginering: | Jaargang 21 (1999) nr. 1-2 pagina's 163-176 |
| Jaar: |
1999-01-01 |
| Inhoud: |
An experimental investigation was carried out with a new array of cement additives, replacing some of the currently used ones. In this study, the cement slurry pressure was monitored during the setting of the cement. Two time-cycles of cement expan sion and contraction were observed. This is due to the individual contribution of each component in the cement mixture. To obtain the optimum tightness of the cement, final contraction in the cycle is crucial for blockage of gas migration. Concentrations of the additives were obtained experimentally in this study for which the cyclic pressure behavior of the cement was optimized and the permeability reduced for the best final cement results. The parameters investigated in this study were as follows: pressure applied on the slurry with time, compressive strength, and permeability of the set cement. The major causes of the early microfractures are the incomplete cement-water reaction, low compressive strength of the set cement, and the sudden change in the hydrostatic pressure as the cement changes its phase from a liquid to a solid state. The fluid loss and free water content were measured and controlled for each sample. Three new cement additives were investigated; one was used to eliminate the microannulus with the pipe while the other two were used to eliminate the microfrac tures within the cement body. An appropriate amount of Ironite Sponge concentra tion eliminated the microannulus with the pipe. The optimum amount of synthetic rubber powder needed during the optimum two-cycle expansion-contraction process was also obtained under reservoir conditions. The Anchorage clay concentration in the mixture that migrates for a limited time minimizes the cement body pores. This concentration can also be optimized. This paper reports the appropriate amounts of X-C polymer, Anchorage clay, Ironite Sponge, and synthetic rubber needed to optimize the compressive strength and eliminate both microfracture and microannu lus. There are certain limits to the amount and type of synthetic rubber powder for which microfractures are eliminated. The article reports an experimental approach that can be used to eliminate gas migration through a cement design that is environmentally safe and inexpensive, using recyclable materials. |
| Uitgever: |
Taylor & Francis |
| Bronbestand: |
Elektronische Wetenschappelijke Tijdschriften |
Details van artikel 11 van 16 gevonden artikelen
| << vorige | volgende >> |