Production - Pressure - Skin - PLT - Permeability - Porosity - Acidizing - IP
Summary: The field of Hassi R' mel is a gas condensate reservoir with a superposition of three layers A - B - C having very good petrophysic characteristics and a rather significant oil rim in the Eastern and Southern peripheries.
Producing wells were drilled in the Northern part - Central - Southern with two lines of dry gas injection.
A decrease in production of the wells was observed in the various zones. Build up tests realised on those wells showed significant skin, which is due primarily to the excessive invasion of the mud used during drilling and Work overs.
For that, a study was undertaken in order to see the method to be used for optimisation and to improve the potential of these wells, which is less than that hoped within sight of their petrophysic characteristics.
A stimulation by acidizing was decided and 3 companies were selected.
34 wells were realised during this campaign, which was carried out in 3 phases in order to diversify the methods.
1st phase 13 wells; 2nd phase 13 wells; 3rd phase 8 wells.
In order to study the effects of stimulation, PLT's were realised before and after the acidizing.
The purpose of this presentation is to show:
Various methods of acidizing used and the concentrations used in each of the 3 phases.
The interpretation of the PLT which enabled us to obtain (flow by level in down hole condition and surface - flowing pressures - static pressures - draw down pressures - index of productivity) which enabled us to calculate the gas profit by level and by well and the gain in pressure.
The resulted synthesis of the PLT's carried out on the acidized wells will be analysed and shown in the form of tables and graphs which will enable us to draw a conclusion on the advantages and disadvantages from this stimulation campaign.
Sandstone matrix stimulation has been the subject of extensive investigations for over 40 years and extensive experimental work has been conducted to investigate the reactions of various mud acid systems with damaging and formation materials1–3 Theoretical analysis and modelling of the stimulation process have also been studied by some investigators4–6.
By this study we want to add another experience on acidizing which is done in the field of Hassi R' mel with different types of acids and various methods of acidizing.
The Hassi R' mel field is a gas condensate reservoir located 500 km South of Algiers and extends on 80 km from North to South and 60 km from East to West.
The 1st producing well was drilled in 1956, and meets a series of sandstone to the depth approximately 2200 m and confirms the existence of a significant accumulation of gas with good petrophysic characteristics and a great extension.
