Q. The samples collected to build a production monitoring study will vary depending on your overall project objectives, the petroleum system, the phases available, and the available budget. For most projects, the key sample type to collect is produced oil, because this is what is usually being produced and, therefore, is the most critical to understand. Produced gas and produced water samples are also potentially important to collect, depending on your objectives, as they provide further insight into compartmentalization and co-mingling. However, given how often produced water is re-used, end-member examples of what is being pumped down should also be collected if waters are of interest. Understanding the hydrocarbon potential and richness of target zones from core and cuttings samples is also very useful, but not crucial.

Field Sampling Tips: In unconventional plays, the wells often share very similar names, with only the numeral altered across pads (1H, 2H, 3H, and so forth). Therefore, labeling of your collected samples and ensuring the correct well head is being sampled is absolutely necessary to project integrity. Mis-labeling, poor labeling, or mis-sampling can set your project back before it even reaches the lab, and adds cost and time to resample the well. The same requirement applies to ensuring the dates are correctly noted on the collected samples; otherwise, assessing changes through time are hindered.

A. Geochemical assessment of your produced fluids can quickly determine if production is generating from discrete fluid compartments, or whether communication is occurring across your target horizons. Where communication is occurring, GeoMark’s SMEs can advise as to whether the cause is geologic or due to production activities. Understanding the geochemical separation of oil from production zones and its variation in context aids in determining the most appropriate well spacing to maximize production and remove, or at least understand, variable production across the area—even from a limited dataset.