Abstract: Where a subsea well is completed for production or water injection service, a subsea christmas tree must sealably connect with both the wellhead and the pipeline(s) or subsea manifold template pipework in order that fluids may flow out of (or into) the well. An intermediate series of pipework loops mounted within a space frame, herein referred to as a Flowline Connection Module (FCM) is removably interposed between the subsea wellhead and the subsea christmas tree to facilitate the piping connections. Each of the modules is further provided with removable U-looped pipework spools at its extremities and said spools may contain adjustable chokes to control the flow of fluids into or out of the wells. The replacement of one choke spool with another may adapt the service function of the well from, for example, production to water injection.