SAND MANAGEMENT SERVICES
Sand Production has been a challenge for the Petroleum Industry for many years. It occurs during hydrocarbon production from a well when the reservoir sandstone is weak enough to fail under the in situ stress conditions and the imposed stress changes due to the hydrocarbon production. The oil or gas flow transports the failed rock causing a variety of problems such as erosion of the surface facilities, well integrity, and sand disposal.
Increased sand production is to be expected with reservoir depletion, increasing water rate, and additional perforation in sand prone layers.
The sand is usually produced in batches of small or large quantities. The characteristic of the batches can vary both in time and from well to well.
The challenge is not merely to stop or avoid sand, but to control sand so that well productivity is optimized. The main goal of sand measurement has been to give a good inline estimate of the amount of sand being produced. It ensures that the tolerance limit of sand production is not exceeded. Many of the oil fields are aging, and with time sand production is increased which causes a strain on the process equipment. There is a strong need for accurate and reliable measurement of sand production.
Sand disposal is also a factor in controlling sand production. If an uncontrolled amount of sand is allowed into the separators, it must be removed on a regular basis. This will lead to down-time of the wells, and sand disposal issues. New regulations require that the sand must be disposed in a controlled manner.
Sand production can lead to erosion and, in the worst case, holes in flow lines. In-line process equipment can be damaged. The separation process can become inefficient when sand is produced and as result the flow lines can partially or completely be blocked if sand settles and forms sand beds. If the sand rate is known, the flow can be adjusted to produce an acceptable sand rate (ASR), maximum sand fraction rates (MSFR) or the introduction of a multi-phase desander. This optimizes production by increasing the production rate.
The first stage in sand management is the sand rate measurement. This is carried out by using non-intrusive acoustic sand monitors clamped to the production pipeline. The outcome determines if the sand rate is within ASR. If it’s greater than ASR, a sample of the produced sand is taken for grain size determination.
The grain size, the rate, and other parameters will be used in the design of a surface desanding equipment for sand removal. In some cases downhole intervention, like installation of sand screens, gravel pack or both may be advised.
The process is captured in the following schematic;
Clients may decide to stop the chain at any stage of the process depending on the client’s objectives. For example, the client may choose to monitor only sand rate, to desander design or to the installation of a desander.