Solids control performance: the KPIs that decide it
You can’t manage what you don’t measure — and most rigs either measure the wrong thing or nothing at all. A handful of numbers tell you whether your solids control is winning or quietly bleeding money into the mud and the waste pit. This is the scorecard.
Why a scorecard beats a gut feel
“The mud looks fine” is not a performance metric. Solids control either removes drilled solids efficiently or it doesn’t, and the difference shows up in cost long before it shows up in the bucket. A few tracked numbers turn an opinion into a decision — and tell you which stage to fix before the next section.
SRE — the master number
Solids removal efficiency (SRE) is the headline: of the drilled solids the bit generated, what fraction did the system actually remove? A high SRE means clean mud, less dilution and lower cost; a low one means you’re carrying drilled solids you’ll pay to dilute away later. It’s the single number that summarises the whole train.
Drilled solids & low-gravity solids
The flip side of SRE is what’s left behind: low-gravity solids (LGS) content in the active system. The lower you hold LGS, the better the mud drills and the less you dilute. Rising LGS is the earliest sign the removal train is falling behind the bit.
Dilution ratio — the truest signal
If you only watch one cost number, watch dilution ratio: how much mud you build or dilute per unit of hole drilled. Poor removal forces dilution, and dilution is expensive. A climbing dilution ratio is removal efficiency failing, expressed in barrels.
Retention on cuttings (ROC)
Retention on cuttings closes the loop on the discharge side: how much valuable mud is leaving with the solids you discard. High ROC is mud (and money) going over the shaker and into the skip. It’s also the number the discharge regulator cares about — performance and compliance in one metric.
Screen life, run hours & cost per foot
Equipment performance shows up as screen life and centrifuge run hours, and it all rolls up into the only number management really feels: mud cost per foot. Every other KPI on this list is a lever on that one. Track cost per foot and you can prove what good solids control is worth.
The scorecard
| SRE | % drilled solids removed — higher is better |
| LGS content | Drilled solids left in mud — lower is better |
| Dilution ratio | Mud built per ft drilled — lower is better |
| ROC | Mud lost on cuttings — lower is better |
| Screen life / run hrs | Equipment performance & cost |
| Cost per foot | The bottom line all of these feed |
Solids control performance isn’t a feeling — it’s six numbers. Track SRE, LGS, dilution ratio, ROC, screen life and cost per foot, and you stop arguing about whether the system is working and start knowing. The rigs that measure are the rigs that improve. Measured, not guessed.
Put it to work
If you want these KPIs set up and benchmarked for your operation — with target ranges for your mud and hole sizes — a remote review can build the scorecard and tell you which lever to pull first.
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Grounded in field solids-control practice and API solids-management principles. Target ranges vary with mud system, hole size and well — treat as engineering guidance.