Normally yes, the network operators can follow the use of each SIM (identity: IMSI) in different mobile devices (identity: IMEI).

The sequence of operations is:
1. SIM is authenticated in AuC then IMEI is retrieved from device
2. Device is validated in EIR which receives IMEI and optionally IMSI
3. SIM is registered in HLR/HSS which receives IMSI and optionally IMEI

These events are logged by mobile operators. By following or filtering the logs it is possible to find out all IMEIs associated with a certain IMSI.

Note that in many countries retaining these event logs is even mandated by law.