Optimisation of scale inhibitor squeeze treatments in fractured wells

Scale inhibitor squeeze treatments are the most common and economically efficient method to prevent scale. The appropriate design of the squeeze job as well as proper selection and placement of inhibitor are crucial for the success of an operation, as defined by the duration of the squeeze lifetime. This paper describes modelling and evaluation of different scenarios of scale inhibitor treatments in hydraulically fractured wells. Considering recent innovations in
scale management techniques, a new model for simulating hydraulic fracturing using solid scale inhibitor particles / scale inhibitor impregnated proppant was developed and compared to a conventional squeeze treatment. This paper considers four different scenarios: a vertical well with one and two fractures and a horizontal well with one and two fractures, respectively. A sensitivity study was performed to determine the key factors to optimize the squeeze design. Three main scenarios were modelled and compared: hydraulic fracturing before squeeze, hydraulic fracturing after squeeze and integrated technique with scale
inhibitor placed into the fracturing fluid. The results concluded that squeeze treatments injected in pre-fractured wells showed the longest lifetimes.