Tezislər / Theses

 

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THE 3
rd
 INTERNATIONAL SCIENTIFIC CONFERENCES OF STUDENTS AND YOUNG RESEARCHERS 
dedicated to the 99
th
anniversary of the National Leader of Azerbaijan Heydar Aliyev
346
CUTTINGS REINJECTION AS AN EFFECTIVE METHOD OF THE 
DRILLING WASTE MANAGEMENT 
Vusala Guluzada 
Baku Higher Oil School 
Baku, Azerbaijan 
[e-mail] 
Supervisor: Rauf Nadirov 
Keywords:
 
waste disposal, cuttings reinjection, environmental consideration of waste 
disposal
 
The latest rigorous legislations do not permit disposing of polluted waste 
straightly into the sea, so that reinjection procedure of exploration & drilling 
mud wastes, particularly the drilling wastes become more feasible option if it 
is possible. By this method, solids are grinded into tiny particles and mixed 
with water (or other liquid) for preparing slurry and then this slurry is pumped 
into underground at such a pressure that is sufficiently high to break the rock. 
There are two practical techniques of slurries injection one of which is into 
the underground through the annulus of the well or into an assigned 
discharge well as illustrated in Figure 1.
Figure 1. 
Offshore reinjection of cuttings (Environmental Aspects of the use and disposal of non-
aqueous drilling fluids associated with offshore oil and gas operation , 2003, May)
These injection methods must be selected with taking financial and 
operational considerations into account. Drilling another valid injection well 

---

THE 3
rd
 INTERNATIONAL SCIENTIFIC CONFERENCES OF STUDENTS AND YOUNG RESEARCHERS 
dedicated to the 99
th
anniversary of the National Leader of Azerbaijan Heydar Aliyev
347
may seem less favorable than annulus injection method due to its costs, 
however more commonly engineers are selecting seperate injection well in 
order not to risk harming their well (Richard C. Haut, 2007). 
With referred to my supervisor practice, this method is broadly known 
also in Azerbaijan where BP company implemented this project succesfully. 
When selecting proper layer for reinjection, it is important to do some test for 
example Leak-off Test and Formation Integrity Test in order to make sure 
that fractured and loosy sand involving layer will be applied. In this practice, 
Surakhani lay (3 km depth) was selected above which is strong formation is 
involved in order not to permit reinjected matter flows into the water seepage. 
This is important and complex work to do beacuse if reinjected cuttings flow 
into the sea, this will be adverse impact to environment and this is not the 
case that is done. So selection of layer should be based on the layer 
sequence where target zone consists of loosy sand and soft geological units 
and above that layer must be strong enough in oder to seal the injected fluids. 
Of course, it is known that as drilling deeper the layers become solider and 
stronger due to compaction however some anomalies can occur and this 
inversion is important in this injection procedure. Moreover, the reinjected 
matter must be lay down and penetrate the faults equally in all directions but 
this fracturing must be implemented laterally not vertically above because 
vertical direction means reinjected cuttings coming to the surface which is 
not desirable consequence of this operation.
The selected formation for discharge have to be mechanically and 
geologically insulated from useful water bodies to prevent waste seepage 
into the water sources. The involved rock cannot be contain petroleum matter 
in significant volumes, however the rock must be satisfactorily porous and 
permeable. The procedure is considered as extremely friendly for ecology 
and more ecomically viable than the cuttings discharge to onshore (S.R., 
2007). Nevertheless, there are possibble cons and pros of this disposal 
technique that are given in tabular form beneath.