wrapfigure environment vspace above figure

The output is precisely what's expected, at least judging from the code.

You can remove the space by setting \intextsep:

\documentclass{article}
\usepackage{lipsum,tikz,wrapfig}

\setlength\intextsep{0pt}

\begin{document}    

\begin{wrapfigure}{r}{4cm}
    \begin{tikzpicture}
        \fill (0, 0) rectangle (4, 4);
    \end{tikzpicture}   
\end{wrapfigure}

\lipsum[1]

\begin{wrapfigure}{r}{4cm}
    \begin{tikzpicture}
        \fill (0, 0) rectangle (4, 4);
    \end{tikzpicture}   
\end{wrapfigure}

\vspace{5mm}
\lipsum[1-2]
\end{document}