SCLEROGLUCANE OF EOR QUALITY

Ziel

Today, the injection of polymers to sweep reservoirs is a confirmed technique in the domain of oil production. In spite of the lack of suitable products, this method is nevertheless restricted to the exploitation of reservoirs of mean salinity and a temperature below 70 deg. C. Significant progress has to be made to ensure the treatment of reservoirs in more difficult environment. Therefore, Scleroglucane, a polymer produced by fermentation, offers new prospects: its resistance to temperature and salinity makes it possible to envisage the treatment of hot and salty reservoirs, still not accessible technically. Scleroglucane is presently available at industrial scale. The purpose of the project is to provide the required quality for the injection of polymers and to define the conditions of implementation of such a product.
PHASE 1 : IMPROVING THE FILTERABILITY OF SCLEROGLUCAN
Completed
Different treatments for the purification - desagregation of scleroglucan have been developed, allowing to produce at pilot scale a polymer presenting satisfactory characteristics under temperature - high viscosity and reduced agregation trend.
Under cold temperature, there remains a residual agregation which provokes poor filterability and requires additional treatment in view of its elimination.
PHASE 2 : ADAPTATION OF FABRICATION PROCESS TO EOR CONSTRAINTS Completed.
The different fabrication parameters likely to agregate the scleroglucane have been systematically explored and optimized in close relation with the studies carried out in phase 1.
The adjunction of purification-desagregation treatments deriving from these studies allowed us to make at pilot scale batches of scleroglucane complying with the EOR needs under hot and salty conditions.
As for the conditioning, studies are underway to prepare powder solutions and concentrate solutions which preserve the good filterability and viscosity characteristics of the initial product. Original methods are being developed.
PHASE 3 : EVALUATION OF THE SCLEROGLUCAN FOR EOR
Evaluations of the behaviour of scleroglucan under flow were continued in a satisfactory manner both in model porous media (pure scleroglucan) and in natural porous media (industrial scleroglucan of EOR quality). They confirm that this polymer is suitable for injection in hot and saline environments. Under cold temperatures encountered at the beginning of the injection, the adsorption is nevertheless reinforced but with no manifestation of a plugging feature.
PHASE 4 : PROTECTION AGAINST BACTERIAL DEGRADATION
Completed.
Studies on the bacterial degradation of the scleroglucan showed that the biodegradation risk decreases as the temperature and salinity raises. Under hot temperature, no bacterial degradation was evidenced. Protection means in risk-proven areas have been defined.
The scleroglucane that is available today, already presents part of the characteristics that are required for the development of a hydrosoluble polymer under EOR. Its solutions are very viscous and highly resistant to shear. Their viscosity is hardly sensitive to salts and to the pH and little or hardly affected by the temperature.
The product only lacks a few adaptations so to meet the EOR quality in view of qualifying for a pilot test.
Therefore, a few obstacles need to be overcome:
- today, scleroglucane presents a poor filtrability which may provoke a risk of clogging the formation in which it will have been injected. Thus, it is necessary to identify the factors responsible for this phenomenon and have them neutralized
- conditioning of hydrosoluble polymers and namely polysaccharides requires a particularly well adapted technique to avoid degradation of the initial filtrability and viscosity of the product. Whether in concentrate solution or in powder form, this conditioningis essential for the development of the scleroglucane and has to be finalized.
- polymer runs many risks of being degraded during its progress in the reservoir, bacterial degradation being one of the major risks. In this case, it is necessary to evaluate the risks and define, when necessary, the means of protecting the polymer.
The project is divided into four phases:
PHASE 1: improving the filtrability of the scleroglucane
The purpose of this activity is to identify the factors that limit the filtrability of the polymer (aggregation factors) to define in a second step the modifications of the manufacturing process of scleroglucane or of other solutions (additives) to improve its filtrability. A detailed study will be carried out on the characteristics of pure polymer, on its structure and on the possible interactions with impurities to identify the endogenous and exogenous aggregation factors.
PHASE 2: adaptation of manufacture process to EOR requirements Works carried out in Phase 1 will lead to a number of modifications in the scleroglucane manufacturing process (fermentation, finalization treatment, conditioning). These modifications will be systematically tested at the plant on a manufacturing pilot. Special care will be given to the finalization of conditioning techniques which do not alter the rheologic and filtrability characteristics of the scleroglucan obtained after process.
Three types of conditioning will be studied, diluted solution directly injectable, concentrate solution and powder solution. PHASE 3: evaluation of the scleroglucane for EOR
The purpose of this activity is to define the performances of the scleroglucane in porous media and the conditions of its implementation in EOR. Studies will first cover pure scleroglucan under model conditions to evaluate the limits of its utilisation domain then in natural porous media with improved filtrability scleroglucan to analyse its behaviour and efficiency when displacing oil.

Programm/Programme

ENG-HYDROCARB 2C - Programme (EEC) of support for technological development in the hydrocarbons sector, 1986-1989

Thema/Themen

1.5 - IMPROVED OIL RECOVERY

Aufforderung zur Vorschlagseinreichung

Data not available

Finanzierungsplan

DEM - Demonstration contracts

Koordinator

GERTH

EU-Beitrag

Keine Daten

Adresse

232 AV. NAPOLEON BONAPARTE
92500 Rueil Malmaison
Frankreich

Gesamtkosten