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Hassi Messaoud oil field is one of the most important fields in Algeria and the world, because it covers an important quantity of total Crude Oil Production in Algeria. Furthermore, two-thirds of this oil field is underexplored or not explored. Therefore, the drilling process of petroleum wells in this field is a continuous process that results in significant drilling waste. This implies that, enormous noxious quantities of drilling waste are produced daily that require treatment via solidification/stabilization (S/S) process before being landfilled. These types of wastes have pollution concentration that significantly exceeds the safety standards. In this study, we focus on the factors affecting the solidification/stabilization treatment of the drill cuttings obtained from Hassi Messaoud oil field and the process optimization. The solidification/stabilization is performed using the cement as binder, sand, silicate, organophilic clay and activated carbon as additives. The study is divided in two steps: (i) aims to determine the optimum ratio of each element used in the S/S process for the organic element (hydrocarbon) elimination, (ii) aims to combine the optimum ratios found in the previous step to determine the optimal mixture. The obtained results in the first step showed that the optimum ratio for the cement-to-drill cuttings mass ratio is 0.09:1. For the additives-to-drill cuttings mass ratio are 0.04:1, 0.006:1, 0.013:1 and 0.013:1 for the sand, sodium silicate, Organophilic clay and activated carbon, respectively. An optimum formula is found which its main finding shows that the hydrocarbon content of our sample is dropped from 9.40 to 1.999%. Many tests results before landfilling were investigated such as matrix permeability, resistance to free compression and heavy metals rate before and after S/S process. Besides that, in the light of outcomes achieved by this assessment these harmful cuttings can be converted into a useful product that helps in reducing the environmental foot prints.

The exploitation of field naturally, leads to decrease the productivity of wells, to continue this exploitation with the best conditions, it is essential to pass to the stage of secondary recovery. The injection of water in reservoir is the most used method in the recovery of oil; unfortunately, there is an incompatibility between the injection water and the reservoir water, which poses a lot of problems such as training mineral deposits. The reservoir waters may contain alkaline ions and be brought into contact with the wash water which contains sulfate ions. The injected water eventually reaches the producing wells and in these wells the mixture is made and the precipitation of barium sulfate (BaSO4) takes place. The crystals then stick in the walls of the tubings, in a process that may be similar to that of sodium chloride, but this time the problem is more serious because it is a very compact deposit insoluble in the water also in acids. Deposits which formed during production and shipping represent a real calamity against which oil producers have been fighting for several decades, deposits causing irreversible damage particularly dangerous for bottom production facilities such as surface and sometimes for the rock itself.

In Hassi Messaoud’s oil industry, the systems which are water based (WBM) are generally used for drilling in the first phase. For the rest of the well, the oil mud systems are employed (OBM). In the field of oil exploration, panoply of chemical products is employed in the drilling fluid formulation. These components of different natures and whose toxicity and biodegradability are of ill-defined parameters are, however, thrown into nature. In addition to the hydrocarbon (HC, such as diesel) which is a major constituent of oil-based mud, we also can notice spills as well as a variety of other products and additives on the drilling sites. These wastes are usually stored in places called (crud wastes). These may cause major problems to the ecosystem. To treat these wastes, we have considered two methods which are solidification/stabilization (chemical) and thermal. So that we can evaluate the techniques of treatment, a series of analyses are performed on dozens of specimens of wastes before treatment. After that, on the basis of our analyses of wastes, we opted for diagnostic treatments of pollution before and after solidification and stabilization. Finally, we have done some analyses before and after the thermal treatment to check the efficiency of the methods followed in the study.

In this article, we present a two-dimensional study of laminar natural convection in porous enclosure. The horizontal walls of the enclosure are thermally insulated, where as the left and right vertical walls are maintained respectively at different temperatures T C (warm temperature) and T f (cold temperature).we present the differential equations modeling the phenomenon studied according to Darcy- Brinkman – Forcheimer model. after the dimensionless form of the equation we have four dimensionless numbers: the Prandtl number P r the thermal Grashof G r , the aspect ratio A, the Darcy number D a . The results allowed us to conclude the following: Increasing of Grachof number with a constant Darcy number, so we areThe increase of convection and as a result the increase in flow velocity and heat transfer.at constant of Grachof number whith decreasing of the Darcy number, the medium is impermeable which slow motion of the convection phenomenon. so we are a degradation speed and heat transfer. Finaly We executed the program calculates with the real data of oil reservoir.

Aquatic ecosystems play an important role on the ecology of arid areas. Their study is necessary for any preservation project. The purpose of this paper is the ecological characterization of seven aquatic ecosystems in south east of Algeria by the determination of physical and chemical parameters of soil and water in addition flora in these environments. The results of water analysis show that studied sites are characterized by an alkaline pH and high salinity (around 213.3 dS/m), they are charged by soluble salts especially chlorides, sulfates and sodium. Studied ecosystems suffer from pollution which is the result of throwing polluted water and rubbish. Soils are wet; contain important percentage of fine sand, their pH is between 6.39 and 8.67. Salinity is very high, it exceeds 57 dS / m. soils are relatively rich in organic matter and gypsum. A systematic sampling of the flora has revealed 11 species belonging to 5 families. The most common plant life forms were Chamaephytes (45%) composed especially with Chenopodiaceae. Keywords: aquatic ecosystems, ecology, Northern Sahara, water, soil, vegetation.